Birkat Hamazon

• On weekdays, some recite Psalm 137, Al Naharot Bavel (By the rivers of Babylon) before Birkat Hamazon. This psalm describes the reactions of the Jews in exile as would have been expressed during the Babylonian captivity (See Mishna Berura quoting the Shelah).
• Psalm 126 Shir Hama'alot (Song of Ascents), which expresses the Jewish hope of return to Zion following their final redemption, is widely recited by Ashkenazi Jews before Birkat Hamazon on Shabbat, Jewish holidays, and certain other days or special occasions (such as weddings, Brit Millah, Pidyon HaBen). Some follow this by two or four additional verses from Psalms (145:21; 115:18; 118:1; 106:2); this addition is known as Tehillat Hashem after its first words, and is based on teachings by the Arizal.[14] (The rumor that these verses were added in order to neutralize the allegedly "Zionist" implications of Psalm 126 is incorrect, as the verses were already recited in the 1600s.[15]) Some Spanish and Portuguese Jews precede Birkat Hamazon with "Ein Keloheinu" on Shabbat and holidays.
• Tzur Mishelo Achalnu is sung in some communities as "an introduction to the Grace after Meals in all joyous occasions."[16] Whereas it is commonly found among the songs printed for singing Friday night,[17] among those who use it for zimun it is never sung in the middle of a meal, since it would signal the meal's end.[16]

Additional sections are added on special occasions.

• On Shabbat the retzei paragraph is recited, just before the end of the third blessing.
• On Jewish holidays, the ya'aleh ve-Yavo paragraph is added in the same place[18]
• On Hanukkah and Purim al ha-Nissim is added to the middle of the second blessing.[19]

If one forgets Retzei or ya'aleh ve-Yavo, one inserts a short blessing before the fourth blessing. If this is also forgotten, then at the first two meals of Shabbat and major holidays (with the possible exception of the Rosh Hashanah day meal), one must repeat the entire Birkat Hamazon. At later meals, or on Rosh Chodesh or Chol Hamoed, nothing need be done.

If one forgets al ha-Nissim, one does not repeat Birkat Hamazon, although one recites a special Harachaman toward the very end, followed by the paragraph Bimei, which describes the respective holidays. If this prayer is also forgotten, nothing need be done.

When birkat hamazon takes place at the Sheva Brachot (seven blessings) following a traditional Jewish marriage, in Ashkenazic communities special opening lines reflecting the joy of the occasion are added to the zimmun (invitation to grace) beginning with Devai Haser; in all communities Sheha-Simchah bi-me'ono is added. At the conclusion of birkat hamazon, a further seven special blessings are recited. While the seven blessings can only be recited with Panim Chadashot (new people who hadn't been at previous celebrations) and in the presence of a minyan, Devai Haser can be recited even without these requirements as long as there is a Zimmun. Furthermore, according to Talmudic law, Sheha-Simchah bi-me'ono (and presumably Devai Haser) can be recited for up to thirty days, or even a year if the meal was made specifically in honor of the couple; nevertheless, this is not practiced today.[20]

At birkat hamazon concluding the celebratory meal of a brit milah (ritual circumcision), in the Eastern Ashkenazic rite, additional introductory lines, known as Nodeh Leshimcha, are added at the beginning and special ha-Rachaman prayers are inserted. In the Western Ashkenazic rite, the Zimmun is recited as normal without any additions, but a long piyyut from Rabbi Ephraim of Bonn is inserted in the middle of the second blessing; special ha-Rachaman prayers are added, but they are different from those of the Eastern Ashekanzic rite.

An abbreviated text is sometime used when time is lacking. It contains the four essential blessings in a somewhat shortened form, with fewer preliminaries and additions. In liberal branches of Judaism, there is no standard text to be recited and customs vary accordingly. Many Sephardi Jews, especially Spanish and Portuguese Jews often sing a hymn in Spanish (not Ladino as is commonly assumed), called Bendigamos,[21] before or after birkat hamazon. An additional abbreviated form of birkat hamazon in Ladino, called Ya Comimos, may also be said.

The Talmud states that women are obligated to say birkat hamazon and that accordingly, three women can constitute a zimmun and lead it.[22] Accordingly, the Shulchan Aruch rules that three women may choose to make a zimmun among themselves, but are not required to do so.[23] However, ten women cannot make the Zimmun B'Shem,[24] and men and women cannot combine to form the three members of an ordinary zimmun.[25] If three men and three women are present, the three men make the zimmun, and the women are required to answer to it.[23]

According to the one opinion in the Talmud,[26] there are special versions of the zimmun if birkat hamazon is said by at least 100, 1000 or 10000 seated at one meal. When 100 are present, the leader says "Blessed is HaShem our God, of Whose we have eaten and of Whose goodness we have lived", and the group responds "Blessed is HaShem our God, of Whose we have eaten, and of Whose goodness we have lived." When 1000 are present, the leader of the Zimmun says "Let us bless HaShem our God, the God of Israel, of Whose we have eaten, and of Whose goodness we have lived", and the crowd responds, "Blessed is HaShem our God, the God of Israel, of Whose we have eaten, and of Whose goodness we have lived." When at least 10000 are present, the leader of the zimmun says "Let us bless Hashem our God, the God of Israel, who dwells among the cherubim, of Whose we have eaten, and of Whose goodness we have lived," and the multitude responds, "Blessed is Hashem our God, the God of Israel, who dwells among the cherubim, of Whose we have eaten, and of Whose goodness we have lived." However, the Shulchan Aruch rules like the other opinion in the Talmud and we do not use any of these variations.[27]

It is customary for the person leading the zimmun to recite the blessings over a cup of wine called the kos shel beracha (cup of blessing). Although sometimes done at ordinary meals, it is more commonly done on Shabbat and Jewish Holidays, and almost universally done at meals celebrating special events. At a Passover Seder, the cup of blessing is drunk by everyone present, and functions as the "Third Cup". The practice of a cup of blessing is mentioned in the Talmud.[28]

Many have the custom - especially after a Shabbat meal - of sharing a Dvar Torah ("word of Torah"; Yiddish, "vort"), before the invitation. This is based on Pirkei Avot 3:3: "If three have eaten at one table, and have spoken there words of Torah, [it is] as if they had eaten at the table of the All-Present, blessed be He..."