Halachipedia - User contributions [en]

Cleaning and Folding Garments on Shabbat

2013-11-18T18:13:04Z

Ike147:

[[Laundering]] garments is a subsection of Bleaching, [[Melaben]] (one of the 39 principle [[Shabbos]] Labors). While [[laundering]] usually entails the use of water and/or cleaning agents, removing dirt from a garment even without these may also fall under the halachic prohibition of [[laundering]].
==Removing dust or dirt particles from a garment==
# If one’s garment became dusty on [[Shabbat]], if one isn’t concerned about the dust on the garment (and would wear it without cleaning it) one may gently shake it out, or gently hit it with one’s hand or dry rag, but one may not shake it out vigorously, rub it, or use a brush.<ref>
* '''Gemara and Rishonim:''' Rav Huna (Gemara [[Shabbat]] 147a) says that one who shakes out his garment has committed a Biblical violation of [[Shabbat]]. The Gemara limits this one who shakes out a black new garment which one is concerned about. Rashi (s.v. Hamenaer) explains that there is a Biblical prohibition of [[Melabain]] ([[laundering]]) to shake out the garment from the dust that was on it, whereas, Tosfot (s.v. Hamenaer) argues that shaking out dust isn’t [[laundering]]. Tosfot, therefore, explains that the Gemara means there is a Biblical prohibition to shake out a garment from the dew which was it. Similarly, the Ritva (s.v. Amar) argues on Rashi that because he says that [[Melabain]] ([[laundering]]) isn't relevant if there's no liquids involved. Biur Halacha D”H Yesh quotes the Shiltei Giborim who asks how Tosfot could permit shaking dust out of a garment if one intends to clean it even though no liquids are used. The Biur Halacha answers that Tosfot only permitted shaking it out without cleaning it directly, however, all agree that rubbing it with one’s hand to clean it is forbidden.
* '''Halacha for Ashkenazim:''' The S”A 302:1 sides with Tosfot that there is a prohibition to shake out a garment from dew that was on it, but there is no prohibition to shake out a garment from dust that was on it. The Rama, however, writes that it’s proper to be concerned for the opinion of Rashi not to shake out a garment from the dust on it. Mishna Brurah 302:6 writes that one may rely on the lenient opinion to ask a non-Jew to do it. Shemirat [[Shabbat]] KeHilchata 15:28 rules like the Rama and Mishna Brurah that one may not shake out a garment from the dust on it, however, if it is a garment which one doesn't usually care about having dust on it, one may shake off the dust gently. He explains that one who shakes off the dust vigorously reveals that he is concerned about the dust. He adds that hitting it gently with one’s hand or a dry rag is the equivalent of shaking it out.
* '''Halacha for Sephardim:''' Yalkut Yosef 302:11 rules like S"A and permits shaking out a garment to remove the dust from it. Or Letzion (vol 2, 24:1), however, writes that we are concerned for the opinion of Rashi and the Rama and so one should only shake out a garment from the dust that's on it if one does so in an abnormal manner, such as if one uses one's sleeve. Ben Ish Chai (Shana Sheniya Vayechi 8) and Kaf HaChaim 302:8 agree with those who are strict for the Rama.
* More on the background of the issue:
* There is a dispute among the Rishonim whether or not removing dust or other dirt particles from a garment is considered [[Laundering]]. Some hold that removing any speck of dirt from a garment, even if it is not absorbed into the fabric of the garment but is merely [[lying]] on its surface [like a feather or a loose thread], is Biblically forbidden since the garment is being transformed from "dirty" to "clean." (Sefer Ha-Zichronos, quoted by Magen Avraham 302:4)
* A second opinion maintains that removing any dirt, whether it is absorbed into the fabric [like dust] or not, is totally permitted, since a dusty garment is not considered dirty and removing the dust is not considered [[Laundering]]. (Tosafos, [[Shabbos]] 147a)
* A third, middle-of-the road view, holds that only dust which is trapped between the fibers of the fabric may not be removed, while dirt which lies on the surface, may. (Rashi, [[Shabbos]] 147a, as explained by Rama and Beiur ha-Gra 302:1)
* The basic halachah follows the middle-of-the-road opinion forbidding one to remove dirt that has been absorbed into the fabric (Rama). Shulchan Aruch ha-Rav and Aruch ha-Shulchan strongly recommend that one be stringent and follow this view [but do not absolutely require it]. Chayei Adam and Mishnah Berurah, however, are of the opinion that the basic halachah is in accordance with this view and one may not be lenient.
* In theory, there may be some dust which lies completely on the surface of the garment and is not absorbed into the fabric. In practice, however, this is almost impossible to determine. [See Shalmas Chayim, 2nd edition, 283, concerning surface dust on shoes.]
* The middle of the road opinion allows removing a feather or a loose thread that has landed on the garment (Rama). A minority view rules like the first opinion that even feathers and threads are prohibited: Magen Avraham, quoted by Chayei Adam 22:9 and Kitzur Shulchan Aruch 80:39; Ben Ish Chai, quoted by Kaf ha-Chayim 302:11. See also Aruch ha-Shulchan 302:9, who rules according to this view in the unlikely event of a person who is reluctant to wear a garment because of the feathers, etc. See Machazeh Eliyahu 44-4.
* Some poskim are concerned with the issue of [[muktzeh]] (See Shulchan Aruch ha-Rav 302:3 and Ketzos ha-Shulchan 116:3). To avoid the problem, the dirt can be removed indirectly or via his body; Sha’ar ha-Tziyun 337:7. Other poskim, however, are not concerned with the [[muktzeh]] issue; see Chazon Ish 47:21 and Shulchan Shelomo 302:5 and 302:12.
* Beiur Halachah 302:1, s.v. lachosh writes that a brush may not be used. Mishnah Berurah 302:6 writes that one should be careful not to let his clothing fall on the ground and get dusty so that he does not come to desecrate the [[Shabbos]].</ref>Some say that nowadays people are particular about their [[Shabbat]] clothes and so one may not remove the dust at all.<ref>Shemirat [[Shabbat]] KeHilchata 15:29 (based on Biur Halacha 302:1 D”H Aleha) writes that a black or dark-colored new looking garment is assumed to be a garment which a person is concerned about and wouldn’t wear without cleaning it and a light colored or old garment is assumed to be garments a person isn’t concerned about. However, if one’s personal attitude is different it would depend on that. 39 Melachos (Rabbi Ribiat, vol 3, pg 708-9) writes that nowadays people are particular about the appearance of one’s [[Shabbat]] clothes even if they are light colored and old and so dust shouldn’t be removed from one’s garments in any way. See Chut Shani 2:33-1. </ref>Sephardim may be lenient to shake out any garment, however, one who is strict should be blessed. <ref>Even though the Ben Ish Chai (Vayechei #8) and Kaf HaChaim 302:8 are strict, Yalkut Yosef ([[Shabbat]] vol 2, pg 76) permits like the opinion of Shulchan Aruch. Menuchat Ahava (vol 2, 12:17) writes that it is permitted but one who is strict should be blessed. </ref>
# If the owner of a dusty garment [that is significantly dirty] has no other suitable clothing and is embarrassed to be seen publicly in such a dirty garment, then the poskim permit one to ask a non-Jew to remove the dust.<ref>Mishnah Berurah 302:6.</ref> While generally one may not ask a non-Jew to do anything that a Jew is not permitted to do on [[Shabbos]], in this case he may, since as stated above, there are opinions that maintain that it is even permitted for a Jew to remove dust from a garment on [[Shabbos]]. [It is questionable, however, whether one may instruct the non-Jew to use a brush.<ref>Since this may be prohibited according to all views. If the non-Jew uses the brush on his own, to make his job easier, he need not be stopped.</ref>]
# If a non-Jew is not available and the owner is embarrassed to be seen in public wearing a dusty garment, some poskim permit a Jew to clean the garment, provided that it is cleaned in an unusual manner, e.g., with one's elbow.<ref>Misgeres ha-Shulchan on Kitzur Shulchan Aruch 80:80, quoted by Minchas [[Shabbos]] 80:143. See Beiur Halachah 302:1 (s.v. lachush), who seems to rely on this only when the garment is clearly not new or newly pressed. See also She’arim Metzuyanim b’Halachah 80:36, who disagrees with this leniency.</ref>

==Removing a stain from a garment==
# Halachically speaking, there are two types of stains:
## a wet stain which is absorbed into the fabric of the garment, e.g., a ketchup stain, and
## a stain which is made when a piece of dirt or food falls on a garment and hardens there.<ref> A third type of stain is one where the food was neither absorbed into the fabric nor dried and hardened; it merely remained on the surface and could be easily flicked off, e.g., a noodle. This type of stain is permitted to be removed according to most poskim quoted earlier, since it is similar to a feather or a loose thread which may be removed.</ref> There are different rules for each of these stains.
# It is forbidden to pour talcum powder or salt in order to absorb an oily stain. <ref> Or Letzion 2.24.2 </ref>
===A wet stain which is absorbed into the garment===
# One may not clean any garment with water, colored water, spit, or any cleaning agent.<ref>Shemirat [[Shabbat]] KeHilchata 15:27, Biur Halacha 302:1 D”H Yesh</ref>
# If no water or cleaning agent is used, then it is permitted to remove the stain if it is insignificant and would not deter the owner from wearing the stained garment. If the stain is significant, however, it is prohibited to remove it if the stain will be removed completely, i.e., it will leave no mark whatsoever on the garment. If, however, the stain is only partially removed—some mark will remain—one is permitted to remove it. Two conditions apply:
## No brush may be used.
## The stain may not be scrubbed away; it may only be gently wiped off with a dry cloth or removed by hand, with a knife, etc.<ref>Entire section based on the view of the Mishnah Berurah 302:11 and 36, and Beiur Halachah, s.v. d’havi. This is also the view of Da’as Torah 302:7. There are, however, poskim who are more lenient and allow a stain to be removed [without water or a cleaning agent] even when it will be completely removed, as long as it is not scrubbed vigorously; see Aruch ha-Shulchan 302:9; Ketzos ha-Shulchan 116:3.</ref>
===Dirt which adheres to the garment's surface===
# If moist mud, chulent, or a similar thick moist substance sticks to one’s clothes, using one’s fingernail or the back of a knife, one may scrape off the substance as long as a stain remains. <ref>Rav Kahana in Gemara [[Shabbat]] 141a says that if mud sticks to one’s garment one may rub it off from the inside but not from the outside. Then the Gemara quotes the Briatta which says that one may scratch it with one’s nail. S”A 302:7 codifies this as halacha. Mishna Brurah 302:32 explains that rubbing it from the inside means holding the inside of the garment opposite where it’s soiled and rubbing two sides of the garment together. Mishna Brurah 307:24 explains that one may scratch it with one’s nail or the back of a knife even from the outside because that’s not considered [[laundering]]. Yalkut Yosef ([[Shabbat]] vol 2, pg 81) agrees. 39 Melachos extends this to chulent or any similar thick moist substance. <br> Shemirat [[Shabbat]] KeHilchata 15:30 (based on Biur Halacha 302:1 D”H Aleha) rules that one may rub it from the inside or scratch it with one’s nail until the mud falls off only if even after removing the mud a stain remains. Shemirat [[Shabbat]] KeHilchata adds that one may gently clean the garment using a dry rag if one is careful not to squeeze out the moisture in the garment. 39 Melachos (vol 3, pg 711-2) agrees but emphasizes that even when using a dry rag one may not remove the stain completely.
</ref>
# If the mud dried on one’s garment one may not rub it off. However, if food whose ingredients were previously ground (such as dough or farina) dried on one’s garment one may remove it with one’s fingernail or back of a knife as long as a stain remains.<ref>The Tur 302:7 quotes Rabbenu Peretz who says that if the mud dried it’s forbidden to rub or scratch it because by making the mud crumble, one violates [[Tochen]]. S”A 302:7 quotes this as an individual opinion. Shemirat [[Shabbat]] KeHilchata 15:31 writes that if food whose ingredients were previously ground (such as dough or oatmeal) dried on one’s garment one may remove it according to the conditions in 15:30. Yalkut Yosef ([[Shabbat]] vol 2, pg 81) writes that in a situation of need and one is embarrassed because of the stain one may rub off dry mud from the inside but it’s preferable to have a non-Jew do it.</ref>
# Even when the prohibition of [[Grinding]] applies, it is permitted, when necessary, to ask a non-Jew to remove this type of stain on [[Shabbos]].<ref>Mishnah Berurah 302:36 and Sha’ar ha-Tziyun 44.</ref>

==Folding Garments==
# It is forbidden to fold garments on [[Shabbat]] unless one has no room in the closet for them or wants to reuse them during the same [[Shabbat]]. <ref>Or Letzion 2.24.4 </ref>
#One may not fold clothing on its creases unless he fulfills the following conditions:<ref>OC 302:3</ref>
##He needs to wear this article of clothing again on [[shabbos]], because he has no other clothing.
##The clothing is new (has never been washed).
##The clothing is white, in which case the folding isn’t as recognizable.
##He folds it by himself, without the aid of another person or a piece of furniture.<ref>MB 14</ref>
#According to many opinions, one may fold clothing not on its creases.<ref>MB 18,19</ref>
#'''Explanation of the Halacha''':<ref>http://www.mesora.org/FoldingTallis.html</ref>
##The Rishonim argue about the reason of the prohibition to fold clothing. The Rambam and Rashi understand that it is a form of ''mesaken mannah'', an action of improving the clothing, which is a torah-prohibition of ''makkah b’patish''. The Ra’avad and Tosfos posit that it is prohibited because it constitutes preparation for the next time one will wear the tallis, and preparation on [[shabbos]] for after [[shabbos]] is prohibited.
##The Aruch HaShulchan<ref>OC 302:10</ref> says that the reasoning of the Rambam and Rashi, that folding is "mesaken mannah" seems to only apply to a professional folding job, or something that will contribute significantly to the permanent improvement of the clothing. He therefore concludes that ''our'' folding should not be prohibited according to the reasoning of the Rambam and Rashi. The reason of the Ra’avad and Tosfos would still apply, though.
##The Ra’avyah<ref>quoted by Mordechai [[Shabbos]] 388</ref> offers a variant differentiation than the Aruch HaShulchan that satisfies even the opinion of the Raavad and Tosfos. If one were to fold not on the creases, his folding is clearly not a mesaken mannah, because it doesn’t improve the clothing, and it is also not a concerted preparation for the next time one will wear the clothing; he is just folding it quickly and haphazardly to be able to fit it into his bag or his shelf. The Ra’avyah, therefore, permits folding clothing (or a tallis) not on the creases.
==Cleaning Muddy Shoes==
# It is permitted to clean muddy shoes before entering one's house on [[Shabbat]]. <ref> Or Letzion 2.24.5 </ref>
==Tablecloths==
# It is permitted to rub and clean a plastic tablecloth on [[Shabbat]] with liquid soap. However, if part of the tablecloth is made from material it is forbidden to clean on [[Shabbat]]. <ref> Or Letzion 2.24.6 </ref>
==Cleaning a Spill==
# If a small quantity of liquid spilled onto the table on [[Shabbat]], it is permitted to wipe the table using a dry cloth provided there is no [[squeezing]] involved. However, it is forbidden to wipe it using a cloth if there was a big spill of liquid. One must use a plastic cleaner. <ref> Or Letzion 2.24.8 </ref>

==Related Pages==
* [[Melabain]]
==Credits==
Special thanks to Rabbi Doniel Neustadt for a section of this article.
==Sources==
<references/>

Required Amount of Matzah and Wine for the Seder

2013-03-21T14:29:45Z

Ike147:

==The four cups of wine==
===How much the cup needs to hold===
# The cup of wine must be filled with a Reviyat of wine and one must drink a full Reviyat or at least majority of a Reviyit. <ref> S"A 472:9. See Rav Schachter at [http://www.ou.org/torah/article/oukosher_pre-pesach_webcast_5770 OU Pre-Pesach Webcast 5770] between minutes 93 and 94 says that people have the misconception that people have to drink a sip of wine, however, one needs to have a Reviyit or at least a majority of a Reviyit. </ref>
# If the cup holds a lot of Reviyot, many people can drink from it, only as many people as there are Reviyot in the cup. <ref> The Orchot Chaim and Kolbo hold that as many people as there are Reviyot can drink from the cup and fulfill their obligation. However, Ramban holds that if the cup holds many Reviyot, one person needs to drink majority of the cup and taken split it up with others. S"A 472:9 rules like the Orchot Chaim and Kolbo. </ref>
===How much must one drink===
# According to Sephardim, one should preferably drink an entire Reviyit which is 2.86 oz (81 grams), however, if that's difficult one may just have majority of a Reviyit which is 1.44 oz (41 grams). <ref> Chazon Ovadyah (pg 16) </ref>
# According to Ashkenazim, one should preferably have an entire Reviyit which is 3 oz (85 grams), however, if that's difficult one may just have majority of a Reviyit which is 1.51 oz (43 grams). <ref>Haggadah Kol Dodi (Rabbi Dovid Feinstein, 5730, pg 4) writes that the [[Reviyit]] for the four cups (using the method of measuring a large egg) should be 3.3oz. Halachos of [[Pesach]] (Rabbi Shimon Eider, Chapter 20, Sec D 5, pg 228-230) writes that since the four cups are Derabbanan one may have the smaller measurement which is measuring by eggs and not by thumbs and according to his calculation a Reviyit should be 3 oz and if one is unable to have a Reviyit one fulfills one's obligation with a majority of a Reviyit. The Laws of [[Pesach]] by Rabbi Blumenkrantz (5771 pg 111) writes that since the four cups are Derabbanan one may use a cup that holds 2.9 oz. See also Weekly Halacha (by Rabbi Neustadt, http://www.torah.org/advanced/weekly-halacha/5760/tazria.html) who writes that one may rely on the view of Rav Chaim Noeh who holds that 3 oz is sufficient being that the cups of wine are Derabbanan. See also
Rav Yisrael Belsky on [http://www.ou.org/torah/article/oukosher_pre-pesach_webcast_5771 OU Pre-Pesach Webcast 5771] between minutes 37 and 38 who says that it's acceptable to consider a Reviyit 4.3 oz and it’s preferable to consider it around 5.8. See also Halachos of [[Pesach]] (pg 229) who writes that the Kiddish cup of Rav Yisrael Salanter was 4.1 oz at it's full capacity and the cup of the Chafetz Chaim was 5 oz. </ref>
# It is preferable to drink the majority of the cup in one drinking. <ref>Magen Avraham 472:11 writes that it's preferable to have the cup of wine in one drinking. Haggadah Kol Dodi (Rabbi Dovid Feinstein, 5730, pg 4) writes that this only applies to the majority of the cup and not the whole cup because a person can't swallow more than a KeBaytzah.</ref>
==Someone who is diabetic==
# If a person is a diabetic and can’t have a lot of wine, the absolute minimum amount is 1.5 oz and a drop more and if one can’t have eat that much one doesn’t have to drink the wine. However, one should consult with one’s doctor who is Torah observant. <Ref> Rav Yisrael Belsky on [http://www.ou.org/torah/article/oukosher_pre-pesach_webcast_5771 OU Pre-Pesach Webcast 5771] between minutes 51 and 52:30 </ref>
===Within what time should one drink the wine?===
# Preferably, one should drink the majority of the Reviyat at one time (without any interruption). <ref> Magan Avraham 472:11, Mishna Brurah 472:34 </ref>
# After the fact, one must drink the cup within the time of a Kdei Achilat Pras (which there are opinions spanning from 2 minutes to 10 minutes) to fulfill the obligation, otherwise one must repeat drinking the wine. <Ref> Rama 472:9 in name of the Rokach quoted by the Bet Yosef writes that one shouldn't drink with a large pause. Magan Avraham 472:11 explains that the long pause is a Kdei Achilat Pras. Mishna Brurah 472:34 rules like the Magan Avraham and adds that even though the Ashkenazi practice is not to repeat to drink the third and forth cup if one forgot to lean because it may look like one is adding a cup to the established cups, even so here one should repeat because one has not fulfilled his obligation according to anyone. </ref>
# Thus, one shouldn't take a cup that has a thin spout because one won't be able drink the whole cup at once. <ref> Rama 429:15 </ref>
===Types of wine===
# If one hates wine or if it gives him a headache (but not if it's going to make him sick in bed) he should try to have the wine to fulfill the mitzvah of the four cups of wine. <ref> S"A 472:10 says that even if one hates wine or it is harmful to his health one should push himself to have the wine to fulfill the mitzvah. Mishna Brurah 472:35 explains that one only has to have it if it gives one a headache but not if makes one sick in bed. </ref>

==Matzah==
# There’s a positive mitzvah Deoritta to eat matza on the night of the 15th of Nissan. <ref>Rambam (Sefer HaMitzot #158) writes that eating matzah nowadays is a Mitzah Deoritta. See Chatom Sofer (CM 196 Hashmatot) who points out that Matzah is the only Biblical mitzvah we have nowadays. </ref>
# There’s a mitzvah (which according to some is Deoritta) in eating more Matzah than the required amount. <Ref>Maharal in Gevurot Hashem chapter 48, Bach 472, Mikrei Kodesh siman 48, Sh”t Har Tzvi 2, and Natai Gavriel (vol 2, 90:26) hold that there’s a mitzvah of eating Matzah as much as one eats even beyond the actual requirement. See also the Emek Shelah (Yitro 53:4). Hagadat Be’er Miryam (pg 53) writes that another reason to eat more Matzah is because there’s a big confusion in the amount necessary and Matzah is a mitzvah Deoritta. Rav Mordechai Willig (Pesach To-Go, Nisan 5771, p. 60) quotes Rav Soloveitchik who derived this insight from the Rambam Chametz UMatzah 6:1.</ref>
===How much Matzah should one eat at the Seder?===
# There's three times one should eat Matzah during the seder: [[Motzei Matzah]], [[Korech]], and [[Tzafun]] ([[Afikomen]]). To fulfill all of one’s obligations, one should eat 2 kezaytim for Motzi-Matza, 1 [[Kezayit]] for Korech, and 2 more kezaytim for Afikomen. All agree that having 2 kezaytim for Afikomen is merely preferable; one fulfills his obligation with 1 kezayit. <ref>
* It is clear from the Gemara (Brachot 37b, Pesachim 108a and 119b) that one fulfills his obligation of eating matza with one kezayit. Rambam Chametz UMatzah 6:1 and Ritva Pesachim 35a write this explicitly. Nonetheless, the Rosh Pesachim 10:30 writes that one should eat a [[Kezayit]] of the whole matza and a [[Kezayit]] of the broken one. This Rosh is codified by the Tur and S”A 475:1.
* Many achronim wonder where the Rosh found a source for requiring two kezaytim. Bach 475:3 suggests that the Rosh was strict for the opinion that one needs to eat a [[Kezayit]] each time one makes HaMotzi (a minority opinion rejected in S”A 210:1). The Prisha 475:1 explains that the Rosh meant since there is a dispute in the Rishonim whether the Al Achilat Matza should be made on the broken one (Rashi Pesachim 116a) or the whole matza (Hahagot Maimon (Seder #7)), one should have a [[Kezayit]] from both. This sentiment is echoed by the Taz 475:2 and Mishna Brurah 475:9.
* Despite the questions of the achronim, the Rosh’s view is accepted by most acharonim, including Magen Avraham 475:4, S”A HaRav (Piskei HaSeder), Kitzur S”A 199:5, Aruch HaShulchan 475:5, and Chazon Ovadyah (p. 65). See, however, Orchot Rabbenu (vol 2, p. 70) who writes that Chazon Ish personally ate only one [[Kezayit]] because he held the halacha doesn’t follow the Rosh.
* For Korech, Mishna Brurah 475:16 writes that a [[Kezayit]] of matza is needed. Kitzur S”A 199:7, Nitai Gavriel 59:1, and Chazon Ovadyah (p. 100) agree.
* Regarding Afikomen, S”A 477:1 rules that one should eat one [[Kezayit]] of matza. Darkei Moshe 477:2 quotes the Maharil that it is preferable to have 2 kezaytim. Magen Avraham 477:1 explains that one is in commemoration of the Korban [[Pesach]] and one for the matza eaten with it. Many achronim quote the Maharil including the Taz 477:1, Kitzur S”A 119:8, Mishna Brurah 477:1, Kaf HaChaim 477:1, and Chazon Ovadyah (p. 106).</ref>
# For Motzi-Matza, many authorities write that if the matzot of the head of the house don’t suffice for 2 kezaytim for each person, one fulfills his mitzvah by eating a bit from the whole matza and 1 other [[Kezayit]] (and not 2).<ref> Rav Shlomo Zalman in Halichot Shlomo 9:40 rules that if the head of the house’s three matzot do not suffice for the [[Kezayit]] for each person, each person should just have a piece from the whole matza and eat a single [[Kezayit]] of matza from other shemura matza. He explains that according to the Prisha, if one isn’t eating from the head of house’s matzot, there’s no safek upon which matza one makes Al Achilat Matza, so there is no need to eat an extra kezayit. Chazon Ovadyah (p. 65), Haggadah Moadim UZmanim (p. 97), and Seder HaAruch (p 455) quoting Rav Elyashiv agree. See also Haggadah Kol Dodi 14:3 and Sh"t Igrot Moshe OC 5:16.</ref>
# Practically, how large in a [[Kezayit]] in terms of the amount of Matzah one should eat?
## According to Ashkenazim, for Motzei Matzah, some say that one should eat 4/5 of a machine matzah, some say 2/3 of a matzah, and others say 1 matzah. For Korech, some say that one should eat 2/5 of a matzah, some say less than 1/2 of a matzah, and others say 2/3 of a matzah. For Afikomen, some say that one should eat 4/5, some say more than 1/2, and others 1 matzah.<ref>
* Mishna Brurah 486:1 writes that Tosfot holds a [[Kezayit]] is half of a KeBeitzah with the shell and the Rambam holds it is a third of a KeBeitzah (see Tosfot (Yoma 80b D”H Agav), Rambam (Eiruvin 1:9)). Rav Avraham Chaim Noeh (Shiurei Torah 3:12) argues that Tosfot holds half a KeBeitzah without the shell. Mishna Brurah 486:1 rules that for Deoritta Mitzvot and Bracha Achrona, one should eat the size of half a KeBeitzah, but for Derabbanan Mitzvot, one third suffices. He adds that since one has to make a Bracha on maror, one should eat half a KeBeitzah.
* The Tzlach (Pesachim 116) holds that the modern day eggs are half the size of those in the days of Chazal. However, Rav Noeh (Shiurei Torah Shaar 3) argues that the modern day eggs have not changed from the days of Chazal. Mishna Brurah 486:1 writes that for the mitzvah deoraitta of matza, one should follow the stringent view of the Tzlach. Even though Vezot HaBracha (pg 6, Birur 1, pg 221) quotes Rav Elyashiv and Rav Shlomo Zalman saying that for Bracha Achrona the widely accepted measurement of the Kezayit is according to Rav Chaim Noeh, in regards to the mitzvah of eating matza, Rav Shlomo Zalman writes in Halichot Shlomo 9:13 that one should be strict for the size of the Kezayit of the Chazon Ish which are based on the opinion of the Tzalach.
* Practically, how much matza is that? The following measurements are in regards to a piece of the average machine matza.
** (1) Halachos of [[Pesach]] (p. 242) quotes Haggadat Kol Dodi (Rav Dovid Feinstein) that for Motzi-Matza, one should eat 6.25”x7” (about one matzah), for Korech 4”x7” (about 2/3 of a matza) and for Afikomen 6.25”x7” (about one matza).
** (2) Rabbi Bodner in Halachos of K’zayis (p. 93) quotes Rav Moshe Feinstein saying that 43.5cc (about 2/3 of a matza) is sufficient for both kezaytim of Motzi-Matza. Rav Yisrael Belsky on [http://www.ou.org/torah/article/oukosher_pre-pesach_webcast_5771 OU Pre-Pesach Webcast 5771] between minutes 30:30 and 37 endorsed this opinion. He added that if one is able, it's preferable to have the larger amount similar to the Chazon Ish's [[Kezayit]]. [Rabbi Bonder (pg 92-95) explains that if one is using hand made matzah it depends on how thick the matzah if which can be determined by seeing how many matzah are in a pound. If there's 9 to a pound, it's thin, 7.5 to a pound medium, and 6 to a pound thick. For Motzei Matzah, if it's thin, use slightly more than half, if it's medium, use slightly more than two fifths, if it's thick, a little more than a third. For Korech, if it's thin, use less than a third, if it's medium use a quarter, and if it's thick use a fifth. For Afikomen, if it's thin, use two fifths, if it's medium use less than a third, if it's thick use slightly more than a quarter.]
** (3) Rav Mordechai Willig (Pesach To-Go, Nisan 5771, p. 60) rules that a [[Kezayit]] is 22.5cc (less than 2/5 of a Matza). See also Am Mordechai Moadim (p. 152).
** (4) Rav Chaim Kanievsky in Shiurin Shel Torah (p. 66, 5750) writes that for the first [[Kezayit]] one should have 2/3 of a matza. (This is a retraction from what he wrote in Shiurin Shel Torah (p. 87, 5716) that a half of a matza is a kezayit).</ref>
## According to Sephardim, some say that the [[Kezayit]] should be measured by the weight of 27 grams, and some say that it is measured by the volume and in weight the [[Kezayit]] comes out to be 20 grams. (The typical machine matzah is 30-32 grams. In general, the [[Kezayit]] can be calculated according to the weight printed on the box.)<ref>
* Kaf HaChaim 168:46 quotes a number of Sephardi Achronim, including the Chida, who say that the minhag of Sephardim is to measure the [[Kezayit]] by weight. He writes that this is the common minhag even for measuring a [[Kezayit]] of matza. Rav Ovadyah in Yechaveh Daat 1:16, Rav Mordechai Eliyahu (Maamar Mordechai 11:96), and Rav Chaim Dovid HaLevi (Aseh Lecha Rav 6:45) agree. Yalkut Yosef 475:4, therefore, rules that a [[Kezayit]] of matza is 27 grams. [In general, one machine matza is between 30 and 32 grams and so a [[Kezayit]] is .85-.9 of a matza.]
* However, Rav Ben Tzion Abba Shaul (Or Letzion vol 3, p 30) argues that the minhag only developed when matza had a similar density to water, but because our matza is thin and dry, there is no need to be stringent to calculate based on weight. Accordingly, he calculated a [[Kezayit]] to be 29cc, which he says is less than 20 grams in weight.</ref>
===Someone who is sick===
# Someone who is sick and can’t eat so much Matzah can use the Kezayit evaluated according to a third of a [[KeBaytzah]] which according to Rav Chaim Noeh is 17.3 cc. <Ref>Mishna Brurah 486:1, Halichot Shlomo (pg 214 note 55) </ref> However, for a personal situation it would be advisable to consult one's Orthodox rabbi to determine the correct amount for one's individual situation.<ref>This is simply good advice so that the Rabbi is able to consider the situation and apply the appropriate leniencies one's individual situation. </ref>
===Crumbs which were caught between one's teeth===
# What stays between one’s teeth isn’t counted towards the [[Kezayit]], however, that which is in one’s gums is counted towards the Kezayit. <Ref>Piskei Teshuvot 486:1, Natai Gavriel (vol 2, 91:7) </ref>

==Sources==
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