Tefillin

From Halachipedia
A pair of Tefillin wrapped in their cases

Putting on Tefillin at home

  1. One who is careful to wear a Talit Katan (Tzitzit) should put on the Talit Katan and Tefillin in one's house and then walk to Shul wearing Tefillin and in Shul put on a Talit Gadol. [1] However, some say that one should only put on one's Tefilin at home if one had put on a Talit Gadol beforehand. [2]
  2. If one will have to pass dirty areas or there are goyim between one’s house and the Shul, one should put on the Tefillin in the hallway next to the Shul itself if possible. [3]
  3. Because the primary concern is to only enter Shul wearing Tefillin, one should have the Tefillin outside Shul from the day before. [4]
  4. Some say that one should also to walk out of Shul wearing Tefillin. [5]
  5. Some say it’s preferable to put on Tefillin outside of Shul even if one will not be one of the first ten in the minyan because of it. [6]

When to put on Tefillin

  1. One may not put on Tefillin before the time of MeSheyakir. [7]
  2. The minhag is to put on Tefillin after having said Birchot Hashachar but preferably before the Shema in korbanot and at least before Parshat HaTamid. [8]

Talit before Tefillin

  1. One should put on Talit before Tefillin.[9] Even if the Talit is only obligated in Tzitzit Derabbanan it still takes precedence to the Teffilin. [10]
  2. If one puts his talit and Tefillin in the same bag, one should be careful to place the Talit to the side of the Tefillin so that one takes the Talit first and then the Tefillin. [11]
  3. If one isn’t going to fulfill the mitzvot of Talit and Tefillin one may pass over one and take the other. [12]Hence if the Tefillin was mistakenly placed above the Talit and one doesn’t plan on fulfilling the mitzvah with them now one may remove both and rearrange it. [13]
  4. Similarly, if one has a Talit of Shabbat in the same bag and above the Talit of the weekday one may take the Talit of the weekday even if it’s below. [14]
  5. If one has only a Tefillin and not a Talit, according to Ashkenazim one shouldn’t wait but rather one can just put on the Tefillin, however Sephardim hold that if one will but will have Talit available to him before the latest time to say Shema, one should wait to get the Talit before putting on the Tefillin. However, if one will not have a Talit available before the latest time for Shema, one should don the Tefillin in order to say Shema with Tefillin in the time. [15]
  6. If one takes off one’s Talit and Tefillin momentarily and then returns one should still put on the Talit first. [16]
  7. If one is wearing Tefillin and then a Talit becomes available, one doesn’t have to remove one’s Tefillin, rather one should just put on the Talit while wearing the Tefillin. [17]
  8. If someone by accident took the Tefillin before the Talit, some say that one should put on the Tefillin since one has it in one’s hands, while others hold one should leave the Tefillin (respectfully), engage in another activity and when one returns one can put on the Talit first. [18]
    1. The same applies if one only took the Tefillin in their bag before taking the talit. [19]
    2. If one has Tefillin in the room that one is in and a Talit in the next room, the principle of not passing up the mitzvah applies and so one should put on the Tefillin first or leave the Tefillin, engage in another activity and then get the Talit first. [20]
  9. If one first made a mistake by taking the Tefillin and then made another mistake by putting down the Tefillin. One should put on the Talit first. [21]
  10. There’s a doubt in a situation where one would we embarrassed to put on Tefillin without a Talit whether one can put on the Talit first. [22]
  11. If one can only afford either a tallit or tefillin, tefillin should be bought. [23]

Kavana (intent) when putting on Tefillin

  1. When putting on Tefillin one should have the following Kavana: Hashem commended us to wear these 4 parshiot (in the Tefllin) which speak of the oneness of Hashem and exodus of Egypt in order that we remember the miracles that reflect Hashem’s totally control over the upper and lower worlds. One should also have intent to make one’s Nishama in one’s brain and the heart which is the seat of emotion and thought, subservient to Hashem, and in this way one will remember Hashem and minimize one’s personal pleasures. [24]
  2. This is certainly an important intent, however one didn’t have such an intent one has still fulfilled their obligation. [25]
  3. It’s also important to have intent that is doing the action in order to fulfill a Biblical obligation. [26]

Torah Sources

  1. The obligation of tefillin is mentioned four times in the Torah. [27]

Who is obligated?

  1. All men above the age of thirteen are required to put on tefillin daily. [28]
  2. Women are exempt because it is a time-bound mitzva.

Arrangement of Paragaphs

  1. There is much discussion among the Rishonim (early authorities) about the order in which the biblical passages should be written in the arm and head tefillin. The rabbis most famous for this dispute were Rashi and his grandson Rabbeinu Tam. Rashi held that the order is: Kadesh Li, VeHaya Ki Yeviehcha, Shema, VeHaya Im Shemoa. Rabbenu Tam held that the last two passages were switched (thus making the following order Kadesh Li, VeHaya Ki Yeviehcha, VeHaya Im Shemoa, Shema). The custom of the world is to follow Rashi's opinion. [29]
  2. However, pious individuals have the practice of wearing both Tefillin of Rashi and Rabbenu Tam. [30]
  3. Unmarried individuals should not wear Tefillin of Rabbenu Tam unless they know that they are capable of having pure thoughts for as long as the one wears Tefillin. [31]

Halachot of the Boxes (Batim)

  1. The straps as well as the boxes should be black. [32]
  2. The tefllin boxes must be square. [33]
  3. In normal circumstances, a sephardi doesn't fulfill his obligation with tefillin written according to minhag ashkenaz. If there is no choice, a halachic authority should be contacted. [34]

Halachot for the Scribe

  1. The passages must be written in order the of the Torah (Kadesh, VeHaya Ki Yiviyecha, Shema, and then VeHaya Im Shamoa). [35] It is preferable to write the passages for the arm Tefillin before writing the passages for the head Tefillin. [36]
  2. Those in the head Tefillin are written on four separate pieces of parchment, while those in the arm Tefilin are written on one piece of parchment. [37]
  3. The parchment must be made from the skin of a kosher type of animal or bird. [38]
  4. The passages must be written with intent that they it should be written for the Kedusha of Tefillin. [39]
  5. The passages must be written with one's right hand if one is a right-handed or ambidextrous, however, a left-handed person must write the passages with his left hand. [40]
  6. The passages must be written with black ink. [41]
  7. It's good to test out the pen before beginning to write a passage. [42]
  8. The passages for Tefillin must be written by a literate religious adult male Jew. [43]

Halachot of the Straps (Retzuot)

  1. The minimum length of the strap for the tefillin for the arm is at least long enough to wrap around the upper arm and extend downwards to the hand and wrapped around the middle finger three times. Preferably though it should be long enough to wrap around the arm six or seven times. [44]
  2. The minimum length of the strap for the tefillin of the head is at least enough to go around the head plus two tefachim on each side going down. [45] The custom is that the right one be longer than the left one and that both go past the midsection. [46]
  3. The straps should be colored black. [47]
  • The coloring should be done for the sake of the mitzva of tefillin. [48]
  • The coloring can be done by a women, or a child if the child is supervised by an adult who instructs him to paint it for its sake. [49]
  • The coloring can be done at night. [50]
  1. One should ensure that the black of the straps is facing outward. [51]

Process of Putting Tefillin On

  1. Right handed people wear the tefillin on their left arm and left handed people place it on their right arm. [52]
  2. The Tefillin of the arm is put on before the Tefillin of the head. [53] Therefore one should be careful to arrange the Tefillin in the case so that one takes the Tefillin shel yad first.
  3. However, if one did take the Tefillin Shel Rosh first one must pass up that Tefillin and put on the Tefillin Shel yad first. [54]

Brachot of Tefillin

  1. Before the strap of the arm-tefillin is tightened, the blessing of להניח תפילין is said. [55]
  2. Upon placement of the head-tefillin, Sephardic and Hasidic authorities are of the opinion that the blessing on laying the head-tefillin is not necessary and the one blessing on laying the arm-tefillin is sufficient. [56]
  3. It is strictly forbidden to talk between the placement of the arm and head-tefillin. [57]
  4. However, if one spoke by mistake, he must recite the beracha of al mitzvat tefillin as the Ashkenaz. [58]
  5. Ashkenazim, however, do recite a second blessing of על מצות תפילין on the head-tefillin, before tightening it around the head‏. [59]
  6. It is also customary to add the phrase ברוך שם כבוד מלכותו לעולם וע‏ד because of the doubt as too the necessity of the beracha. [60]

Where the Tefillin are placed

  1. The arm-tefillin is placed on the biceps of the arm, two finger breadths away from the elbow, with the box facing inward towards the heart. [61] After the beracha is said, the arm-tefillin is tightened, then wrapped around the arm seven times. The knot formation and arm binding differ considerably between different traditions. There is a custom to cover the arm-tefillin with the sleeve, in accordance with the verse "And they will be a sign to you...", i.e. to you and not to others.
  2. Next, the head-tefillin is placed on top of the head, "between the eyes" but not lower than the hairline (or if balding, where one's hairline once was). The knot of the head-tefillin sits at the back of the head, upon the part of the occipital bone that protrudes just above the nape. The two straps of the head-tefillin are brought in front of the shoulders, with their blackened side facing outwards.

Wrappings around the hand

  1. The Tefillin Shel Yad should be put on the left arm on the area where the muscle bulges in the lower half of the area between the elbow and armpit. [62] One should make sure not to put the Tefillin within two fingerbreadths of one’s elbow. [63]
  2. The Tefillin should be tilted slightly towards the body so that when the arm is bent the Tefillin faces the heart. [64]

detached

  1. The knot which looks like a Yud on the Tefillin Shel Yad should be facing inward and touching the main Tefillin box. [65]
  2. The Minhag is to put the Maavarta (bridge) part of the Tefillin facing the shoulder. [66] The Maavarta should also be below halfway between the elbow and armpit. [67]
  3. It’s better that the Maavarta is placed above halfway between the elbow and armpit and not have the main box of Tefillin be within 2 fingerbreadths of one’s elbow. [68]
  4. Many authorities are lenient not to require a Netilat Yadayim if one touches the skin in the area where the Tefillin Shel Yad is placed or rub one’s hair while putting on Tefillin Shel Rosh, [69] however, some are strict. [70]
  5. Nothing can interpose between the Tefillin or the area where the straps wrap around the arm and one’s body, however, in the area of the knot one may have an interposition. [71]

Physical Separation/Chatzitza

  1. One should ensure that there is no interposition between the Tefillin Shel Rosh and one's head or the Tefillin Shel Yad and one's arm. [72]
  2. The following are considered items that separate between the Tefillin and one's body: loose dirt [73], water in your hair [74], a wig [75] a toupee [76], and long hair.[77].
  3. A wristwatch does not need to be removed. [78]

Proper conduct while wearing Tefillin

  1. It is forbidden to laugh or come to lightheartedness while wearing Tefillin because it remove one’s concentration from the Tefillin altogether. [79]
  2. It’s preferable not to remove one’s thought from the Tefillin at all so as not to come to think bad thoughts. However, during Davening and learning one doesn’t need to keep one’s mind on Tefillin since one will certainly maintain a proper seriousness and fear of Hashem. [80]
  3. If one is not engaged in learning or praying and is still wearing the Tefillin one should occasionally touch one's Tefillin in order to keep one's attention focused to the Tefillin. [81] One should touch one's Tefillin Shel Yad and then the Tefillin Shel Rosh. [82]
  4. It is forbidden to go to sleep while wearing Tefillin unless one covered the Tefillin and isn’t with one’s wife. [83]
  5. It is customary to fast if one's tefillin fall to the floor even if it was accidental. [84] In some cases instead of fasting, it is better to give charity, or do a taanit dibur, or learn for additional hours, and therefore a posek should be consulted. [85]
</ref>

Eating while wearing Tefillin

  1. It’s permitted to eat a snack while in tefillin even nowadays when we don’t wear the tefillin all day. [86] Some are strict not to have even a snack, but permit if one is eating or drinking for in intent to wear the tefillin while learning or Davening extra. [87]
  2. The size of a snack is a Kebaytzah of bread or mezonot; so too, one shouldn’t have more than a kebaytzah of intoxsicating drinks. However, drinks that aren’t intoxicating, like coffee and tea, are permitted even more than a kebaytzah. [88]

When to Wear Tefillin

  1. Originally tefillin were laid all day, but not during the night.
  2. Nowadays the prevailing custom is to lay them only during the weekday morning service. [89]
  3. The minimum requirement is to have Tefillin on during Kriyat Shema and Shemonah Esrei. [90]
  4. The problem with wearing them all day is the necessity to remove them when encountering an unclean place and the requirement to constantly have in mind the knowledge that they are being worn.

Borrowing Tefillin

  1. One may borrow somebody's tefillin without receiving the owner's permission, as long as the owner is not there to ask permission from. [91] This doesn't apply if the owner placed them in a place where it's obvious he doesn't want them being used, or if someone uses them on a permanent basis. [92] Also, after borrowing the tefillin one must place them back wherever they were. [93]
  2. One may not remove the borrowed tefillin from the synagogue or the owner's home without permission. [94]
  3. Obviously one may not damage the tefilli.n [95]
  4. One doesn't however fulfill his obligation with stolen tefillin and cannot recite a beracha on them. [96]


Shabbat and Yom Tov

  1. Tefillin are not worn on Shabbat and the major holidays including Pesach, Shavuot, Rosh Hashanah, Yom Kippur and Sukkot. The reason given that these holidays are themselves "signs" which render the use of tefillin, which are to serve as "signs" themselves, superfluous.

Chol Hamoed

  1. The minhag of some Ashkenazim is to wear Tefillin on Chol HaMoed, however, the minhag in Israel and minhag of Sephardim is not to wear Tefillin on Chol HaMoed. [97]Someone who doesn’t have a minhag should not wear Tefillin on Chol haMoed. [98]
  2. One who wears Tefillin should stipulate before wearing the Tefillin that if there’s an obligation then I wish to fulfill that obligation, and if not, I have no intention of fulfilling the mitzvah with my action. [99]
  3. If one wears Tefillin on Chol HaMoed one shouldn’t wear Tefillin of Rabbenu Tam (even if one usually wears Tefillin of Rabbenu Tam). [100]
  4. Some authorities hold that if some people in the Shul wear Tefillin and others don’t there’s a violation of Lo Titgodidu (don’t cause factions in observance of Torah) and so they advise that one should either find a shul that has your minhag or pray in different locations in the same shul. [101]

References

  1. Based on the Zohar Vaetchanan 265, the Shulchan Aruch 25:2 rules that one who is careful to wear a Talit Katan should put on the Talit Katan and Tefillin in one's house and then walk to Shul wearing Tefillin and in Shul put on a Talit Gadol.
  2. Halacha Berura (Rav David Yosef, 25:11) quotes the Ari"zal as saying that even if one is wearing a Talit Katan one must put one's Talit Gadol before putting on one's Tefillin at home and adds that it's good to follow this latter opinion.
  3. Mishna Brurah 25:8+10, Sh"t Rav Pealim OC 1:4
  4. Kaf HaChaim 25:17, Piskei Teshuvot 25:6
  5. Piskei Teshuvot 25:6
  6. Ben Ish Chai Vayera #5, Kaf HaChaim 25:18, Halacha Brurah 25:13, Yalkut Yosef (Tefillin 25 note 36)
  7. S"A 30:1
  8. Kaf HaChaim 25:3-4
  9. S”A 25:1 says that the Talit goes first because we want to increase in Kedusha from Talit to Teffilin.
  10. Mishna Brurah 25:1, Halacha Brurah 25:7, Ben Ish Chai Vayera Halacha 3
  11. S"A 25:1 writes that one must not place the Tefillin above the Talit because otherwise one may take the Tefillin before the Talit. However, Halacha Brurah 25 writes that it's not respectful to the Tefillin to place the Talit above the Tafillin, therefore it should be placed in a separate bag or to the side of the Tefillin.
  12. Mishna Brurah 25:3 writes that the law that one can’t pass up a mitzvah only applies when one intends to do the mitzvah.
  13. This follows clearly from the above Mishna Brurah but is written as an example in Halachot of Tefillin by Rabbi Shlomo Churba (page 7) quoting Or Letzion (vol 2, 44:16).
  14. Kaf HaChaim 25:8 writes that since one doesn’t intend to use the Talit of Shabbat now one is permitted to take the Talit of the weekday even if it’s below.
  15. Rama 25:1 writes that if one has Tefillin but not Talit one shouldn’t wait for the Talit but rather just put on the Tefillin. The Magan Avraham 25:2 understands that this is the case even if there’s no concern that one will miss Sof Zman Kriyat Shema. so rules the Mishna Brurah 25:7. However, the Machaneh Chaim (Mehudra Kama 2), Sh”t Shenot Chaim 36, Kaf HaChaim 25:10, Yalkut Yosef (Sherit Yosef 1 pg 319), and Halacha Brurah 25:10 argue that one should wait to put on the Talit as long as one will not miss the time for Kriyat Shema.
  16. Mishna Brurah (Biur Halacha D”H Vayitztarech) writes that the principle that one should put on Talit before Tefillin is true also in a case where one took off the Talit and Tefillin momentarily and now comes to put on Talit and Tefillin. This is quoted in Yalkut Yosef (Sherit Yosef 1 pg 318), Halacha Brurah (Birur Halacha 25:2), Amudei HaShulchan 10:2, and Divrei Shalom (vol 1 pg 15).
  17. Ben Ish Chai (Vayera 4, Sh”t Rav Poalim 1:4) writes that if someone is only wearing Tefillin and a Talit becomes available, one should remove one’s Tefillin before putting on the Talit. So holds the Sh”t Torah Lishmah 1. However, the Rama 25:1 writes that if one has only Tefillin one should put that on and when one gets a Talit one should don the Talit implying that one doesn’t need to remove the Tefillin in order to put on the Talit. So rules Yalkut Yosef (Sherit Yosef 1 pg 319).
  18. The S”A 25:1 writes that one should be careful not to put the Tefillin above the Talit in one bag because then one may take the Tefillin first and have to put them on before the Talit. The S”A here holds that since one picked up the Tefillin the principle of not passing up a mitzvah overrides putting the Talit on before the Tefillin. Most achronim rule in accordance with S”A including Mishna Brurah and Halacha Brurah 25:9. However, the Kaf HaChaim 25:10 writes in name of the Arizal that one should always put on the Talit first even in such a case. Therefore, the Sh”t Or Letzion 2:44:16 writes that one should leave the Tefillin and engage in another activity, so that when one returns to the Tefillin one may put on the Talit first according to all opinions. [This advise of engaging in another activity in order to remove the issue of not passing up a mitzvah is sourced in the Magan Avraham 25:4 and Mishna Brurah 25:3.] Even though the Halacha Brurah 25:9 argues that once one is involved in a mitzvah one isn’t allowed to engage in a non-mitzvah, still the Divrei Shalom (vol 1 pg 23), Yalkut Yosef (Sherit Yosef 1 pg 315-7), and Halachot of Tefillin (by Rabbi Shlomo Churba pg 8) rule in accordance with the Or Letzion.
  19. Magan Avraham 25:1 argues that the principle of not passing up a mitzvah doesn’t apply if one takes the Tefillin in their bag before taking the Talit. So holds the S”A HaRav 25:3. However, Kitzur S”A 10:2, Maamer Mordechai 25:3, Nehar Shalom 25:1, Nishmat Adam 13:2, Levush 25, Taz 25:10, Eliyah Rabba 25:4, Chaye Adam 13:1, Shalmei Tzibbur (pg 37a), Siddur Bet Ovad (Makom Hanachat Tefillin 1), Kaf HaChaim 25:6, and Mishna Brurah (Biur Halacha 25:1 D”H Shelo Yanichu) rule that the principle of not passing up a mitzvah applies even if the Tefillin are still in their bag.
  20. Mishna Brurah 25:4 writes that the principle of not passing up on a mitzvah applies even to when one mitzvah is in the room that one is in and the other mitzvah is in another room. Therefore the same halacha as when one picks up Tefillin before Talit applies as above.
  21. Mishna Brurah 25:5, Halacha Brurah (Birur Halach 25:2)
  22. Mishna Brurah (Buir Halacha 25) writes that if one is embarrassed to put on the Tefillin first there is a doubt whether one may put on the Talit first. Yalkut Yosef (Sherit Yosef 1 pg 318) writes that since we hold that the principle of not passing up a mitzvah is only derabbanan, we override the Derabbanan with Kavod HaBriot. [whether not passing up a mitzvah is derabbanan or deorittah is a dispute in the rishonim and achronim, see Yalkut Yosef (Sherit Yosef 1 pg 317-8).]
  23. Kaf Hachayim 25:3
  24. S”A 25:5
  25. Mishna Brurah 25:16
  26. S”A 60:4
  27. The torah mentions Tefillin twice when recalling the The Exodus from Egypt as in Exodus 13:9 it reads "And it shall be for a sign for you upon your hand, and for a memorial between your eyes, that the law of the LORD may be in your mouth; for with a strong hand did the LORD bring you out of Egypt." and Exodus 13:16 "And it shall be for a sign upon your hand, and as totafot between your eyes; for with a mighty hand did the LORD bring us forth out of Egypt." and twice in the first two paragraphs of Kriat Shema as in Deuteronomy 6:8 it says "And you shall bind them as a sign upon your arm, and they shall be as totafot between your eyes." and lastly in Deuteronomy 11:18 "You shall put these words of mine on your heart and on your soul; and you shall tie them for a sign upon your arm, and they shall be as totafot between your eyes."
  28. The Rambam(Sefer HaMitzvot Mitzvah Aseh 12 and 13) and Sefer HaChinuch (421) record this as a mitzvah that applies to every male individual even nowadays. Rambam there says based on the gemara in Menachot 44a that one who is obligated to wear tefillin but doesn't, transgresses eight commandments (4 for the hand and 4 for the head).
  29. Shulchan Aruch 34:1, Halacha Brurah 34:1
  30. S"A 34:2-3 rules that that the especially pious should wear both sets, but added that only one commonly known to be especially pious may do so, so as not to appear as arrogant in one's piety. However, Halacha Brurah (Rabbi David Yosef, 34:1) writes that since it has become the practice of many common people to wear both Tefillin of Rashi and Rabbenu Tam it's not considered an issue of arrogance to wear both pairs of Tefillin.
  31. Halacha Brurah 34:2
  32. S"A 33:3
  33. S"A 32:39
  34. Halacha Berura 32:148
  35. S"A 32:1
  36. Rama 32:1
  37. S"A 32:2
  38. S"A 32:12
  39. S"A 32:19
  40. S"A 32:5. See Mishna Brurah 32:18 who quotes the Pri Megadim that preferably one shouldn't have a sofer who writes with the right hand and does other activities with the left hand or the opposite.
  41. S"A 32:3
  42. S"A 32:22
  43. S"A 32:30 and S"A 39:1
  44. S:A 27:8. Mishna Berura 27:31 says the custom nowadays is seven times.
  45. Mishna Berura 27:44
  46. Mishna Berura 27:41
  47. S"A 33:3 says that this is a halacha limoshe misinai. Mishna Berura 33:19 says they should be as black as a raven and adds that one should be especially careful at the spot where one tightens the tefillin as the paint there wears off easily.
  48. S"A 33:4. Rama writes that they are not even kosher bidieved if they are not colored black for the sake of the mitzva. Biur Halacha 33:4 "pasul" says they should be repainted with the proper concentration.
  49. Mishna Berura 33:23
  50. Rav Yosef Shalom Elyashiv and Rav Chaim Pinchas Scheinberg quoted in Mivakshei Torah volume 4 page 415.
  51. S"A 27:11. Mishna Berura 27:38 says that one really only has to make sure that the part around the head and around the arm muscle has the black on the outside but it looks nicer to make sure the whole thing is that way.
  52. S"A 27:1, 27:6
  53. Ben Ish Chai Vayera Halacha 6 says that this order has great kabbalistic significance as well. Chazon Ovadia Chelek 2 page 209 says that the order relates to the idea of naase vinishma (Shemot 24:7, that the Jews accepted to observe the commandments and only afterwards understand them, because the tefillin shel yad represent our actions and the shel rosh represent our understanding
  54. S"A 25:5
  55. S"A 25:8
  56. S"A 25:5
  57. S"A 25:9
  58. S"A 25:9
  59. Rama 25:5
  60. Rama 25:5
  61. S"A 27:1
  62. S”A 27:1, Mishna Brurah 27:4
  63. Piskei Teshuvot 27:1 quoted Tefillah LeMoshe 7:7
  64. S”A 27:1
  65. S”A 27:2
  66. S”A 27:3
  67. Piskei Teshuvot 27:1 inferring from Mishna Brurah 27:34
  68. Piskei Teshuvot 27:1 quoting Shraga HaMeir 6:46
  69. Halichot Shlomo (Tefillah 4:3), Sh”T Shelmat Chaim 39-40, Kaf HaChaim 4:59
  70. Piskei Teshuvot 27:2 quoting Dinim Vehanahot LeChazon Ish 3:10 and Chelkat Yehoshua 6:7
  71. S”A 27:4, Mishna Brurah 27:16
  72. Bet Yosef 27:4 quotes a dispute between the Rosh (Hilchot Tefillin 18, Sh"t HaRosh 3:4) who says that that there may not be any interposition between the Tefillin Shel Rosh and one's head and the Tefillin Shel Yad and one's arm and the Rashba (Megillah 24b D"H Sipah) who allows putting Tefillin on top of an interposition. [See the Sh"t HaRashba Sh"t 3:282 where at first he acknowledges the explanation of the Rosh but comments that this is the halacha lo lemaaseh and continues to explain his own explanation until he concludes that his approach is the halacha.] S"A 27:4 rules like the Rosh. The Rama 27:4 says that this only applies for the batim (boxes) themselves and not the retzuot (straps) but Mishna Berura 27:16 says that one should not be lenient in this. S"A 27:5 says though that if one needs to lenient for some medical reason and needs a head covering, he can wear them above a thin hat. The Rama there says in that case he can't say a beracha.
  73. Mishna Berura 27:14
  74. Shaare Teshuva 27:6 says one should make sure to dry his hair well if he wet it before putting on the tfillin, both because it could damage the tfillin, and because the water itself could be considered a separation.
  75. Mishna Berura 27:16
  76. Iggerot Moshe OC 4:40 says that if removing it in public would embarrass the person that he should put on Tefillin in private with a beracha without the toupee and then go to shul and put it on there over the toupee without a beracha but hair that is transplanted it is considered part of the head and is not a problem. see Daily Halacha (by Rabbi Mansour).
  77. Machatzit Hashekel 27 and Kitzur Shulchan Aruch 10:6 say that although short hair would not be a problem, excessively long hair could be. The Pri Megadim 27 says that hair which is not located in its place of growth but rather has been brushed across from another part of the head, constitutes a chatzitza in tefillin. Mishna Berura 27:14-15 agrees to this, and says that it also could be hard to keep the Tefillin lined up between the eyes and at the right height with long hair. Aruch Hashulchan 27:14 and Rav Ovadia (Yechave Daat 2:2(22)) hold that there is what to rely on regarding really long hair. The Aruch Hashulchan says only hair moved from another place would be problematic.
  78. Sh"t Yechave Daat 3:2, Yabia Omer 2:2 and Rav Ovadia writes that one who is stringent will be blessed. Emes liYaakov OC 27:note 31 says even though the Rama 27:4 based on the Teshuva of the Rashba 1:827 says one doesn't need to worry about barriers except for between the skin and the boxes, that if one is accustomed to removing it he should continue doing so, as there are some poskim who are stringent on barriers on any part of the arm or head tefillin
  79. Chaye Adam 14:15 and Mishna Brurah 44:3
  80. Mishna Brurah 44:3 writes that it’s preferable not to remove one’s mind from the Tefillin at all while wearing them so as not to comet to bad thoughts. Biur Halacha (D”H yashan) explains (based on Or Zaruha 585) that during Tefillah and learning one will certainly have a fear of heaven and not come to lightheartedness.
  81. S"A 28:1 writes that occasionally one should touch one's Tefillin in order to make sure that one's attention doesn't shift from thinking about the Tefillin. Mishna Brurah 28:1 writes that while one is praying one doesn't need to touch one's tefillin for this purpose. Mishna Brurah 44:3 adds that the same is true while one is learning.
  82. S"A 28:1. Mishna Brurah 28:3 explains that this order was chosen in order that when one's hand (the one not wearing Tefillin) touches the Tefillin it doesn't pass over the closer mitzvah of touching the Shel Yad first.
  83. S”A 44:1
  84. Mishna Berura 40:3, Iggerot Moshe OC 3:3. Daat Torah 44:1 however quotes poskim who say that fasting is only necessary if they fell because of negligence. Baer Heitev 571:1 and Kaf hachayim 40:6 write that it is preferable for one to fast on the day that the tefillin fell. Kaf Hachayim 40:7 writes that one doesn't need to fast at all if the tefillin fell from less than 3 tefachim high.
  85. Az Nidberu 8:20 and Rivevos Efrayim 6:14 quoting the Steipler. Daat Torah 44:1 writes that if fasting is too hard for somebody they can be lenient and give charity and this is the case for someone who is physically weak, a torah scholar or teacher as well as somebody who is active in the community. This is also the opinion of the Chida in Chayim Sho’al 12, Ben Ish Chai Parashat Chayei Sarah halacha 18, Sh"t Yabia Omer 2:28
  86. S”A 40:8 writes that it’s permitted to have a snack while wearing tefillin. Mishna Brurah 40:19 quotes the Shulchan Shlomo who has a doubt whether this applies nowadays since we don’t wear tefillin all day. However, the Sh”t Teshurat Shai 215 argues that we shouldn’t extend a prohibition based on our own logic.
  87. Piskei Teshuvot 40:8
  88. Mateh Yehudah quoted in Mishna Brurah, kaf hachaim 40:35
  89. S"A Orach Chaim 37:2, Rambam Hilchot Tefillin 4:26
  90. S"A 25:4
  91. Rama 14:4, Chesed La'alafim 14:4 based on the idea that somebody is happy to have his belongings used for a mitzva. Kaf Hachayim 14:19 says this only applies if the owner is not present to ask permission from him.
  92. Kaf Hachayim 14:27
  93. Kaf Hachayim 14: 22
  94. Chesed La'alafim 14:4
  95. Kaf Hachayim 14:22
  96. S"A 25:12, Mishna Berura 25:54
  97. S”A and Rama 31:2, Sh”t Yabea Omer 3:5(3)
    • Some rishonim forbid tefillin to be laid on Hol HaMoed as they consider the days have the same status as a festival which in itself constitutes a "sign" making the laying of tefillin unnecessary. These Rishonim include: Baal Halachot Gedolot (cited by Tosafot Moed Katan 19a D"H Rabbi Yosi), Rambam (Hilchot Yom Tov 7:13; explained by Kesef Mishna), Rashba (Sh"t HaRashba 1:690), and Ri (cited by the Hagahot Maimoni Hilchot Tefillin 4:9).
    • Other rishonim argue and hold that Chol HaMoed does not constitute a "sign" in which case tefillin must be laid on Hol HaMoed. These Rishonim include: Rambam, Rosh (Hilchot Tefillin 16), Or Zarua 1:589, and Maharam of Rothenburg cited by the Mordechai.
    • The Bet Yosef writes that the minhag of Sephardim is not to wear Tefillin on Chol HaMoed based on Kabbalistic sources. This is also the opinion of the Vilna Gaon (Bi'ur ha-Gra Orach Chayim 31:2 s.v. V’yesh Omrim).
    • The Tur (Siman 31) quotes some rishonim who are uncertain whether one must lay tefillin on Chol HaMoed and concludes that one should wear Tefillin without a Bracha. These opinions include the Ritva (Eruvin 96a), Smag (Eruvin 153), Meiri (Moed Katan 18b), and Taz 31:2. The Mishna Berura recommends that on Hol Hamoed one make a mental stipulation before donning tefillin: If I am obligated to don tefillin I intend to fulfill my obligation and if I am not obligated to don tefillin, my doing so should not be considered as fulfilling any obligation; and that the blessing not be recited. The Rama writes that the Ashkenazic custom is to wear Tefillin with a Bracha which is to be made in an undertone. See further: [[1]].
  98. Sh”t Teshuvot VeHanhagot 2:332
  99. Mishna Brurah 31:8
  100. Mishna Brurah 31:8
  101. Hilchot Chol HaMoed Zichron Shlomo (in the hebrew section pg 39-40) has a letter from Rav Moshe Feinstein, dated Kislev 5737, stating clearly that one should follow the minhag of the Shul and if the minhag is to wear Tefillin one should also. However, Rav Moshe Feinstein in Sh”t Igrot Moshe O”C 5:24 (pg 79 D”H Al Kol Panim) dated Kislev 5743, writes that in crowded shuls where there’s many who wear Tefillin and many who don’t there’s no issue of Lo Tasu Agudot since it’s clear that there’s two different minhagim. However, Rav Moshe adds that preferably someone who is praying in a shul that wears Tefillin should also wear Tefillin. Sh”t Teshuvot VeHanhagot 2:332 holds that there’s no real issue of Lo Titgodedu but preferably one should be concerned for those who hold that it’s an issue. Rabbi Schachter on yutorah.org (min 36-7) ruled that it is an issue for some people in one minyan to wear Tefillin and others not to wear Tefillin, however, two minyanim in one shul may not be an issue.