This is the approved revision of this page, as well as being the most recent.
Birkat HaMazon is a special prayer said after eating a meal with bread, thanking God for the food He has given us, as well as beseeching Him to keep providing for us, among other Tefillot. It contains several blessings, composed by numerous people, including Moshe Rabbeinu, Yehoshua, King David, and Rabban Gamliel. Special insertions are made for the Yamim Tovim, Shabbat, Chanukah, and Purim.
Minimum Amount of Bread to Be Obligated in Birkat HaMazon
- One is not obligated to recite Birkat HaMazon unless one eats a minimum of a Kezayit of bread. The amount of bread necessary in order to make HaMotzei and Netilat Yadayim are discussed in the articles specific to those topics.
- How large is a kzayit of bread? According to Ashkenazim the Kezayit is slightly less than one ounce of volume. A good approximation is half the center piece of a 1 lb rye bread. According to Sephardim the Kezayit is 27 grams in weight. For more specific halachot about Kezayit, see the Halachot of Kezayit.
Who Is Obligated to Say Birkat HaMazon
- There is a dispute whether women are obligated in Birkat HaMazon on Torah level or only Rabbinically. Therefore, if a woman ate bread and is full and is now unsure whether she said Birkat HaMazon, there’s is a dispute whether she should say it to be sure and there’s what to rely on to make it to be sure. Additionally, a woman can fulfill the obligation of a man if he listens to her Birkat HaMazon, however, she shouldn’t fulfill his obligation if the man ate to satisfaction but rather one if he ate a Kezayit and not to satisfaction.
- A child, who isn't yet Bar Mitzvah'ed, is obligated to say Birkat HaMazon on a derabbanan level because of Chinuch.Therefore, a child can't fulfill the obligation of an adult who doesn't know how to say Birkat HaMazon unless the adult didn't eat until he was satisfied, otherwise the adult is obligated on a deoritta level to say Birkat HaMazon and can't fulfill his obligation with that of a child.
- Some say that children from the age of 6 should say Birkat Hamazon.
Clearing the Table in Preparation for Birkat HaMazon
- One must not remove the tablecloth or the bread from the table until after those who have eaten have recited Birkat HaMazon; otherwise, he will never experience Hashem's blessing.
- Nowadays, it is sufficient to leave crumbs for this purpose.
- If one eats a sandwich and is not seated at a table then he should leave some bread in his lunch box for Birkat HaMazon so that it will be possible for Hashem's blessing to come to him.
- If no bread remains one should place some other bread on the table.
- Some have the practice of removing the knife before birkat hamazon. This applies on Shabbat and weekdays, and with plastic or metal knives. This is not necessary for al hamichya of boreh nefashot after a snack.
- One shouldn't clear the table while saying Birkat Hamazon but after the fact if one did one does fulfill one's obligation.
Behavior During Birkat HaMazon
Interruptions in Birkat HaMazon
- One shouldn’t interrupt Birkat HaMazon at all to answer or greet someone.
- According to Ashkenazim, one should finish before the mezamen (the one who lead the Zimmun) finishes each Bracha so that one can answer Amen to his Bracha. However, the Sephardic minhag is not to answer Amen during Birkat HaMazon.
- One shouldn't interrupt in the first three Brachot of Birkat HaMazon to answer Kaddish, Kedusha, or Barchu. However, in the middle of the fourth Bracha one may answer Kaddish or Kedusha as long as one already said Baruch Atta Hashem Elokenu Melech HaOlam and part of the middle of the Bracha.
- It is proper not to interrupt in middle of the Harachaman section of Birkat HaMazon. However, according to the strict halacha it is permissible to interrupt at that point, yet if one is making Birkat HaMazon over wine one shouldn't interrupt.
- It is permissible to answer Kaddish, Kedusha, or Amen to a Bracha in the Harachaman section of Birkat HaMazon.
Position for Birkat Hamazon
- One should sit during Birkat HaMazon whether one ate while seated or standing for at least the four Brachot of Birkat HaMazon.
- If one was traveling on the road and ate while traveling he may say Birkat HaMazon also while traveling.
- One should sit while making a Bracha Achat Mein Shalosh at least when it’s for Mezonot (Al HaMichya).
- It’s forbidden to say Birkat HaMazon or any Bracha while doing work.
- Some say that one should wear a hat during Birkat Hamazon. There is a dispute if the same is true of Al Hamichya.
Saying Birkat HaMazon Out Loud
- One should recite Birkat HaMazon loud enough that one can hear oneself say the words, however if one said it quietly one fulfills one’s obligation as long as one enunciated the words with one’s lips and didn’t just read or think it.
- It’s better to say Birkat HaMazon out loud in order to inspire having proper intent and also because on Shabbat and Yom Tov it’ll help ensure that one doesn’t forget to add the appropriate paragraphs.
If One Left The Location Where He Ate
- If one ate and left that place intentionally, one must return to the place where one ate and if one made Birkat HaMazon in the second place one has fulfilled one’s obligation after the fact. If one ate and left that place unintentionally, one should return to the place where one ate unless there’s a great need.
- This is only the case if one doesn’t have bread with him in the second place, however, if one has bread in the second place, one may eat it there (eat a piece even if it’s less than a Kezayit) and then make Birkat HaMazon there. (This doesn’t mean that one may leave one’s place initially but only in a after the fact situation.) 
- According to Ashkenazim, Al HaMichya should be said in the place where one ate and so if one left it would have the same law as Birkat HaMazon.
If One Is Unsure if He Recited Birkat HaMazon
- If one ate and was full and now is unsure whether one recited Birkat HaMazon, preferably one should have another Kezayit (upon which one should wash and say HaMotzei) and then say Birkat HaMazon, however, the strict law is that one should said Birkat HaMazon in cases of doubt. Some say that if a person was full because of all of the food he ate and not because of the bread alone he shouldn't repeat Birkat Hamazon if he's in doubt. Others don't distinguish.
- If a person ate bread and is full but is in doubt whether he said Birkat HaMazon, one must go back and say Birkat HaMazon. According to Ashkenazim, one should say the entire Birkat HaMazon, whereas according to Sephardim, one should only say the first 3 Brachot.
- If a person ate a Kezayit of bread but wasn’t full, and now is in doubt whether he said Birkat HaMazon he shouldn’t go back and make Birkat HaMazon, but it’s preferable to wash again, make Hamotzei, eat a Kezayit and make Birkat HaMazon.
- If a person ate bread and is still thirsty because he didn't drink enough during the meal and now has a doubt whether he said Birkat HaMazon, some say he should repeat Birkat HaMazon and some say not to repeat it.
- A woman who ate bread and is unsure whether she said Birkat HaMazon, she should hear it from someone else or wash again and make another HaMotzei to remove herself from doubt. However, if that's impossible, Ashkenazim hold that she may say Birkat HaMazon, but according to Sephardim she is not supposed Birkat HaMazon out of doubt.
How Long Does One Have to Recite Birkat HaMazon?
- If one ate bread and is full, preferably one should make Birkat Hamazon within 72 minutes and after the fact, one may make it as long as one is full from what one ate. However, after 72 minutes, if one is a little hungry, one can no longer make the Birkat Hamazon. 
- If it’s past 72 minutes and one is in doubt whether one is still full one can make Birkat Hamazon, yet, it’s preferable to eat another Kezayit before making Birkat Hamazon. 
- However, if one just had a Kezayit and was not full, one should try to make the Birkat Hamazon right away and if one didn't one may only make Birkat Hamazon up to 72 minutes after one ate.  Some add that if one waited more than a half hour it's preferable to have another Kezayit of bread before making Birkat Hamazon. 
- If one has a very long meal and continues to have appetizers or drinks, one may make the Birkat Hamazon as long as the meal continues even 4 or 5 hours.  One should have something to eat or drink every 72 minutes, however, if one didn't then one may still say Birkat Hamazon. 
- If someone was at a wedding and ate the main course and danced for a while the time lapse before it is too late to say birkat hamazon can be extended by eating or drinking something. 
One Who Does Not Know Birkat HaMazon In Its Entirety
- If one only knows the first three Brachot of Birkat HaMazon one should say those Brachot, however, if one only knows some of the first three Brachot but not all of them, according to Sephardim, he shouldn’t say Birkat HaMazon at all, but according to Ashkenazim, if he was full then he should say the Brachot he knows.
Regarding Reciting Birkat Hamazon While Drunk
Reciting Birkat Hamazon in the Presence of Feces or Urine
- It’s forbidden to say any Bracha or Torah within 4 amot of feces. However, after the fact, if one said Birkat HaMazon one should say Birkat HaMazon again, but if one said Birkat Mazon within 4 amot of urine one doesn’t go back to make Birkat Hamazon.
Making Birkat HaMazon Over Wine (Benching Al HaKos)
- It’s preferable to make a Birkat HaMazon over a cup of wine when making a Zimmun of three. If you are saying birkat hamazon alone, it should not be done over a cup of wine.
- Although there doesn't seem to be any differentiation between Shabbat and Yom Tov as opposed to a regular weekday, some people have the practice to use a cup of wine only on Shabbat and Yom Tov.
- When reciting Birkat Hamazon over a cup of wine, one should raise up the cup of wine a Tefach.
- However, if one doesn’t have wine in the house one may use Chamar Medina (a drink which is drunk in the country but isn’t water).
- If one drank from the cup of wine the cup is considered tainted and unfit for making on it Birkat HaMazon until one fixes it by filling it up with wine or water.
- The cup used in making Birkat HaMazon over wine should be washed out in the inside and outside before it is used, however, if it is already clean it doesn't need to be cleaned.
- The cup of wine should be filled up completely.
- The cup of wine must have a Reviyit as a minimum, but it is preferable to have it filled up completely. Some have the practice to fill it up so that it spills over the sides and some don't fill it up so much that it spills over.
- If one doesn't have a cup of wine or grape juice for making birkat hamazon over a cup of wine one may nonetheless eat the meal and it isn't necessary to fast.
Bracha of the Guest (Birkat HaOreach)
- A guest should bless the homeowner who provided the food for the meal. The Ashkenazic minhag is to recite shortened bracha "הרחמן הוא יברך את בעל הבית הזה" but it is better to recite the full text of the bracha "יהי רצון שלא יבוש ולא יכלם בעל הבית הזה לא בעולם הזה ולא בעולם הבא ויצליח בכל נכסיו ויהיו נכסיו מוצלחים וקרובים לעיר ולא ישלוט שטן במעשי ידיו ואל יזדקק לפניו שום דבר חטא והרהור עון מעתה ועד עולם".
- Some say that children should recite the bracha of guests for their parents, whether they're unmarried or married.
- It applies equally to the one leading the zimun and everyone else.
- Someone paying for his meal doesn't need to recite the bracha of a guest.
- Some say that yeshiva students eating a meal paid for by the donors to the yeshiva should say the bracha of a guest for the donors. Others however hold that they are exempt.
- Someone who had his meal sponsored and is now eating in another place according to some poskim he should nonetheless recite the bracha of a guest on behalf of the one who paid for the meal. Others say that he's exempt.
- The minhag is to say the bracha of a guest after the harachaman's. However, some say that it is should be said immediately after the fourth bracha.
- The bracha of a guest is said on Shabbat and Yom Tov and it isn't considered asking requests on Shabbat since it is part of the regular brachot we say everyday.
- The practice is that on days Musaf is not recited in davening, the pasuk recited at the end of Birkat Hamazon is recited as magdil (מגדיל) yeshuot malko, while on days that Musaf is recited, it is changed to Migdol (מגדול) yeshuot malko.
- At the end of Birkat HaMazon for Melava Malka, some authorities hold that one should say say "migdol yishuot malko" like on shabbat itself, instead of "magdil yishuot", while others say that one should say the regular "magdil yishuot" on Melava Malka just like during the week.
In any Language
- It’s preferable to say Birkat HaMazon in Hebrew, but strictly speaking it is permissible to say it in any language one understands.
- Shulchan Aruch O.C. 168:9, 184:6, and 210:1
- Halachos of Brachos Addendum 1, pg 246
- Yalkut Yosef 158:4. See the Kezayit age for more opinions about whether Sephardim follow weight or volume.
- Shulchan Aruch 186:1, Mishna Brurah 186:3. See Shitat HaKadmonim (last page of bava kama) referenced on the Mitzvot_Aseh_SheHazman_Grama page regarding the obligation of women in Birkat HaMazon.
- Shulchan Aruch 186:2. Rav Moshe HaLevi (Birkat Hashem v. 2, p. 317) writes that after the fact a child who said the Birkat HaMazon in order to fulfill the obligation of an adult has fulfilled his obligation. Rabbi Mansour on dailyhalacha.com quotes this as halacha.
- Shulchan Aruch 186:2. Mishna Brurah 186:6 writes that a child shouldn't fulfill the obligation of a woman because perhaps the woman's obligation is deoritta whereas the child's is only derabbanan. Mishna Brurah 186:7 adds that there is a dispute whether a child who didn't eat to satisfaction can fulfill the obligation of an adult considering that the child is only obligation by force of two derabbanan factors. He concludes that one should be stringent.
- Rabbi Mansour on dailyhalacha.com writes that parents should ensure that children from the age of 6 say Birkat HaMazon.
- Shulchan Aruch 180:2 based on the Gemara in Sanhedrin 92a which says that if you don't leave bread on the table you will not see a sign of blessing. Mishna Brurah 180:2 writes that this is so we can have bread ready in case poor people come in hungry. Contemporary Questions in Halacha and Hashkafa pg. 90, Yalkut Yosef, Berachot II, 180:1
- Yalkut Yosef, Berachot II, 180:3, Az Nidabru 11:46:2
- Yalkut Yosef, Berachot II, 180:3
- Rabbi Eli Mansour
- Shulchan Aruch 180:5. See Rabbi Mansour's article for several different explanations of this custom.
- Rabbi Eli Mansour
- Sh"t Rivivot Ephraim 1:136:2
- Yalkut Yosef 183:10
- S”A 183:8 writes that some say that in regards to greeting or answering someone, Birkat HaMazon is judged like Shemona Esreh when one doesn't interrupt to answer anyone. Halacha Brurah 183:28 writes that this opinion quoted in Shulchan Aruch is accepted as Halacha. The Mishna Brurah 183:1 explains that Birkat HaMazon is similar to Shemona Esreh in that it may only be said in one place and not while one is moving.
- Halacha Brurah 183:27
- Yabia Omer 1:11, Yalkut Yosef 183:5
- Yalkut Yosef O.C. 183:1 (vol 3, p 265).
The Ben Ish Chai (Chukat Halacha 18) writes that it is forbidden to speak about mundance matters, and adds that this is especially true if one plans to say birkat hamazon Al Hakos (with a cup of wine).
- Yalkut Yosef (vol 3, p 265)
- Shulchan Aruch O.C. 183:9, Mishna Brurah 183:31, Tosafot Berachot 51b, Chazon Ovadia Berachot page 84, Kitzur Shulchan Aruch 44:6. Shulchan Aruch mentions that it should be recited sitting in order to have the proper intent and one shouldn't be lying down but rather it should be recite with awe.
- Shulchan Aruch 183:11, Mishna Brurah 183:36
- Shulchan Aruch 183:10, Mishna Brurah 183:35 quoting the Gra
- Shulchan Aruch O.C. 183:12, Mishna Brurah 183:37
- Mishna Brurah 183:11
- Dirshu 183:11 cites the Steipler, Rav Chaim Kanievsky, and Rav Chaim Zonenfeld that one should wear a hat for Al Hamichya, while Rav Shlomo Zalman and Rav Sheinberg held that one didn't have to.
- S”A 185:2, Mishna Brurah 185:2, Chazon Ovadia Berachot page 94, Mikor Chaim 101:2. Birkei Yosef 185:2 as well as the Shaare Teshuva 185:1 say in the name of the Sefer Charedim that if you cannot hear yourself most poskim hold that you didn't fulfill your obligation and based on that the Chesed La'alafim 185:1 and Ben Ish Chai Chukat 7 says that you should eat more bread and say birkat hamazon. However, Chacham Ovadia Yosef in Chazon Ovadia Berachot page 94-95 says this is based on a mistaken understanding of the sefer charedim and most poskim including rif, rambam, rosh, behag, sheiltot, eshkol, Smag, Raah, Meir, Ra'avyah, Or Zarua, Rabbeinu Yerucham, Orchot Chayim, Riaz, Tur and Shulchan Aruch all hold that you have fulfilled your obligation as long as you enunciated the words with your lips and therefore you wouldn't need to go back to eat more bread.
- Mishna Brurah 185:3
- S”A 184:1, Mishna Brurah 184:5, 184:7
- S”A 184:2
- Mishna Brurah 184:12 quoting the Gra
- Shulchan Aruch 184:4, Mishna Brurah 184:15, Kaf HaChaim 184:15, Yalkut Yosef 184:3
- *Pri Megadim E"A 184:8 has a doubt whether someone who was full because of the rest of the food he ate is obligated in Birkat Hamazon biblically or he is only biblically obligated if he is full because of the bread. Tzlach Brachot 48a s.v. mdkatal assumes like the second explanation of the Pri Megadim. Biur Halacha 184:6 s.v. bkezayit cites the Pri Megadim but discusses whether the Radvaz 6:2224 (cited by Shaarei Teshuva 197) is a proof against the Pri Megadim. The Radvaz says that if one completed becoming full on bread he is biblically obligated to say Birkat Hamazon and he isn't clear whether one started to eat other food or bread as part of another meal. Chazon Ish OC 34:3 agreed with the Pri Megadim and says that one isn't biblically obligated unless one is primarily full on the bread. Daf Al Hadaf Brachot 48a cites Kitvei Madmor Mgur 33 from the Sfat Emet who rejects the proof from Brachot 48a and sides with the Pri Megadim. Divrei Shalom OC 2:46 has the same rejection.
- Daf Al Hadaf Brachot 48a cites Kovetz Bet Aharaon Vyisrael 16:5:9 who tries to prove that all foods combine to a biblical obligation of Birkat Hamazon from Rashi (though Rashi is in disagreement with the Bahag). Also cited there are the Halachot Ketanot 2:227 and Keren Ldovid 48 who agree. Baal Hameor Brachot 29a s.v. amar seems to be a clear proof against the Pri Megadim. Divrei Shalom shows how the Baal Hameor might not be a proof. Igrot Moshe OC 4:41 agrees with Halachot Ketanot. Halacha Brurah (Otzrot Yosef 7:6) holds that although it is a dispute if one is in doubt one should repeat Birkat Hamazon since there is a safek safeka, since some rishonim hold that eating a kezayit generates a biblical obligation, and even according to the other rishonim some hold that all of the foods in the meal combine to a biblical obligation. He quotes that his father in Halichot olam (v. 2 Chukkat n. 6), Yechava Daat 6:10 in note, and Chazon Ovadia Brachot p. 238 agrees.
- Based on the Pri Megadim, Divrei Shalom concludes that if a person has a doubt if he said Birkat Hamazon and was only full because of the other foods and not just because of the bread he shouldn't repeat the Birkat Hamazon. Ben Ish Chai Chukkat 10, Kaf Hachaim 184:24, and Or Letzion 2:13:6 agree.
- Shulchan Aruch 184:4 rules that if a person is in doubt whether he said Birkat HaMazon he has to go back and say it since Birkat HaMazon is deoraitta we don’t apply the general rule of Safek Brachot Lehakel. Mishna Brurah 184:13 based on Magen Avraham 184:7 comments that when one repeats the benching one must say all four Brachot even though the fourth one is only derabbanan so that people don’t disregard its importance. see also Pri Chadash 209 who brings a different reason that you should recite even the 4th beracha. However, the Sephardic acharonim including the Kaf HaChaim (184:15), Sh"t Ohr Letzion 2:13:4, and Yalkut Yosef (Brachot pg 282) argue that since the fourth Bracha is derabbanan we apply the rule of Safek Brachot without concern for a remote possibility of those who will degrade the fourth Bracha.
- Shulchan Aruch 184:4. Mishna Brurah 184:15 writes that according to many Rishonim only if one ate and is full is one biblically obligated, therefore if one only had a Kezayit and is in doubt whether he said Birkat HaMazon one shouldn’t go back and say it out of doubt, rather it’s preferable to wash again, make hamotzei, eat a Kezayit and make Birkat HaMazon. This is also the opinion of Yalkut Yosef (Brachot 286, 184:5) and Yabia Omer OC 8:22:13.
- Rashi Brachot 48a s.v. cites the Bahag that a person isn't obligated biblically to recite Birkat Hamazon unless one was full. Rabbinically one is obligated once one ate a kezayit. Rashi agree with the Bahag about that. Tosfot 48a s.v. ad, Tosfot Sukkah 26b s.v. vlo agree, Rosh Brachot 7:24, and Rambam Brachot 1:1 agree. However, Rashba Brachot 48a s.v. ha and Raavad Brachot 5:15 hold that there's a biblical obligation to recite Birkat Hamazon even if one just ate a kezayit and it doesn't depend on whether one was full.
- Yalkut Yosef (Brachot pg 289, 184:8) writes that since the opinion of Shulchan Aruch is that even if one is still thirsty the obligation of Birkat HaMazon is Deoritta, in cases of doubt one should go back and say Birkat HaMazon. However, Kaf HaChaim 184:26, Ben Ish Chai, and Or Letzion 13:6 hold that since there's an opinion that Birkat HaMazon is only Derabbanan if one is still thirsty one shouldn't go back and say Birkat HaMazon. Rama 197:4 cites the opinion of the Mordechai that if one was thirsty and didn't drink one's obligation in Birchat Hamazon is only rabbinic. He is only concerned for his opinion initially.
- Ben Ish Chai Chukat 9, Kaf HaChaim 184:25, Sh"t Ohr Letzion 2:13:4, Rabbi Ovadyah Yosef in Sh"t Yacheve Daat 6:10, and Halacha Brurah 184:10 (explained in Sh"t Otzerot Yosef 7:7) hold that a woman is possibly obligated Deoritta (Brachot 20b) and so in a case of doubt we revert to the rule of Safek Brachot and so a woman wouldn't return and make the bracha. However, the Mishna Brurah 186:3 holds that there's enough to rely on for a woman to go back and make Birkat HaMazon if she wants. This is also the opinion of Rabbi Binyamin Zilber quoted in VeZot HaBracha (pg 351).
- Teshuva M'ahava 2:234 writes that since it is a safek safeka (similar to the case of Shach's klalei safekot YD 110:16) the woman should be exempt like the Pri Megadim 186 E"A writes about this case. Halacha Brurah (Otzrot Yosef 7:7) has the same logic. However, he believes that she should make the birkat hamazon since (1) according to the Rif she's obligated to recite birkat hamazon from the Torah, (2) even if it is a safek if she's obligated like the Rambam, perhaps she can recite the bracha since potentially making a bracha levatala is only derabbanan and (3) fulfilling a mitzvah which is the bracha itself when there is a doubt and a potential biblical obligation is permitted even according to the Rambam. His conclusion is that she can recite the birkat hamazon but it is better for her to eat more and repeat birkat hamazon or to read the birkat hamazon without enunciating the words with her lips (hirhur).
- Shulchan Aruch OC 184:5 writes that one may Birkat Hamazon until one is hungry again. Vezot HaBracha (pg 49, chapter 5) and Yalkut Yosef (Brachot pg 300) rule that if one didn’t make Birkat Hamazon until after 72 minutes, one may surely recite Birkat Hamazon as long as one is still full and one isn't hungry. Vezot HaBracha quotes Rav Elyashiv who says that it’s preferable to eat a little more before making Birkat Hamazon. Aruch HaShulchan 184:7 and 8 writes that since we don't know the precise determination of when we're still full must make Birkat Hamazon within 72 minutes and if one didn't then one should eat another Kezayit and then say Birkat Hamazon. Kaf HaChaim 184:28 writes that in order to fulfill all opinions if it has been 72 minutes one should eat another Kezayit and if one doesn't have bread one may make Birkat Hamazon as long as one is full.
- Mishna Brurah 184:15, Vezot HaBracha (pg 49, chapter 5)
- Yalkut Yosef (Brachot pg 300), Mishna Brurah 184:20
- Vezot HaBracha (chap 5, pg 50)
- Mishna Brurah 184:18, Vezot HaBracha (chap 5, pg 50), Yalkut Yosef (Brachot pg 301)
- Vezot HaBracha (chap 5, pg 51) quoting the Magen Avraham 184:9
- Vezot Habracha p. 249 quotes Teshuvot Vehanhagot 1:175 as saying that flavored water can extend this time period. See Har Tzvi 96 and Shevet Halevi 6:27.
- Shulchan Aruch OC 194:3, Mishna Brurah 194:13
- S”A 185:4, Mishna Brurah 185:7-8
- Shulchan Aruch O.C. 182:1, Kitzur Shulchan Aruch 45:1, Mishna Brurah 182:4.
The Gemara in Pesachim 105b states that Birkat Hamazon requires a cup of wine but does not explain when. Shulchan Aruch 182:1 quotes 3 opinions from the Rishonim:
- Even an individual who is reciting Birkat Hamazon should do so with a cup of wine. This is the opinion of Tosfot Pesachim 105b s.v. shma, Tur 182:1, Rabbenu Yerucham 16:7, and Rabbenu Yonah Brachot 37b s.v. gemara cited by Bet Yosef.
- Only when 3 people are together, must they recite it over a cup of wine. This is the opinion of the Ri and Rabbenu Elchanan cited by Hagahot Maimon Brachot 7:15:60.
- Even 3 people are not required to. This is the opinion of the Rambam Brachot 7:15, Rif 26a, Ran 26a s.v. gemara, and Smag 27 cited by Hagahot Maimon and Bet Yosef.
- see previous note. Although the Tur writes that one should have a cup of wine even when reciting birkat hamazon alone, the Zohar Bamidbar 245b clarifies that there's no obligation to make a birkat hamazon over wine unless there is at least a zimmun of three. Yalkut Yosef 182:1 cites the Zohar and adds that one shouldn't do a birkat hamazon over a cup when he is saying birkat hamazon himself but if one still wants to, he shouldn't pick up the cup.
- See Rivevot Ephraim 1:150 who suggests that this could be that since we are not technically obligated to use a cup of wine for even with 3 people, people only really make an effort to be strict in this regard when they have more free time on Shabbat and Yom Tov. Yalkut Yosef 182: 1: in the footnote adds that it could be because we are trying to get to 100 berachot.
see also Rabbi Ari Zivotovsky regarding special occasions
- Shulchan Aruch 183:4 states that when making Birkat Hamazon over a cup of wine one should raise it up a Tefach.
- Kitzur Shulchan Aruch 45:1, Mishna Brurah 182:14
- Shulchan Aruch O.C. 182:3 and 182:6
- Shulchan Aruch 183:1
- Rama 183:2
- Rama 183:2, Mishna Brurah 183:9
- Tur 182:1 writes that if one doesn't have enough wine for birkat hamazon over a cup of wine he should fast. However, Magen Avraham 182:1 disagrees. Also, Shulchan Aruch records the opinions that doing a zimmun isn't absolutely necessary, it is just preferable. Mishna Brurah 182:2 concurs with the Magen Avraham.
- Gemara Brachot 46a. Smag Asin 27 and Avudraham (Birchat Halechem s.v. vamrinan) cite a source from chazal that learns the idea of blessing the homeowner from the pasuk ואכלת ושבעת וברכת את ה' that את includes the bracha of a guest for the homeowner. Encyclopedia Talmudimit (Orach fnt. 72) cites the same from the Roke'ach 319.
- The full text is found in the Gemara Brachot 46a and is codified by Shulchan Aruch 201:1. The Mishna Brurah 201:5 points out that the minhag is to recite a shortened text of the bracha but really we should recite the longer one. Piskei Teshuvot 201 fnt. 9 cites the Teshuvot Vehanhagot 2:122 writes that the Griz was careful to say the text of the Gemara. He also cites the Sidur Yavetz who disapproves of the shortened text.
- Magen Avraham 201:2, Kaf Hachaim 201:13, Piskei Teshuvot 201:1, Vezot Habracha p. 143 quoting Rav Elyashiv
- Piskei Teshuvot 201:1 in clarifying the Magen Avraham.
- Aruch Hashulchan 201:3, Ben Ish Chai (Shana Rishona Shalach 24). Shaar Hatziyun 201:15 also writes that he doesn't know why the Magen Avraham holds that it only applies to the one leading the zimun but the minhag is that everyone says it.
- Magen Avraham 201:2, Kaf Hachaim 201:11, Aruch Hashulchan 201:2
- Or Letzion 2:46:33
- Vezot Habracha p. 143 quotes Rav Elyashiv as saying that the yeshiva students are exempt since there's no specific homeowner. Shevet Halevi 11:51 writes that the yeshiva students are exempt since we don't fulfill others in birkat hamazon with zimun and maybe there's no obligation of a bracha of a guest today and also the homeowners don't eat with the students. See there for more reasons. He concludes that they are exempt from the actual text but should still bless the donors out of gratitude. Piskei Teshuvot 201 fnt. 5 points out that according to the Shulchan Aruch Harav 201:4 that there's no obligation of a bracha of a guest when the homeowner isn't eating with them.
- The Piskei Teshuvot 201:1 cites the Mekor Chaim of Chovot Yair 193:3 that a guest should recite the bracha even if the homeowner isn't there.
- Shulchan Aruch Harav 201:4 writes that a guest is exempt if he's not in front of the homeowner. Vezot Habracha p. 143 quotes Rav Mordechai Eliyahu that the minhag is only to recite the bracha of a guest when eating with the homeowner.
- Vezot Habracha p. 143 citing Rav Mordechai Eliyahu
- Griz (Likutei Hagriz 2:13 cited by Dirshu 201:5), Bet Baruch 125 cited by Vezot Habracha p. 143
- Divrei Shalom 2:49 based on Bet Yosef 188:4 quoting the Shibolei Haleket
- Ben Ish Chai Year 1, Parashat Chukat: Halacha 19 writes that this is based on mystical reasons
- Kaf Hachaim 189:11
- Yalkut Yosef (Kitzur Shulchan Aruch 300:4)
- S”A 185:1, Mishna Brurah 185:1