There are accepted opinions that rule one is not obligated to eat bread by Shalosh Seudah. Based on this, one is no required to repeat Birchas Hamazon if Retzei was omitted.

There is an interesting discussion regarding what should be added when Rosh Chodesh falls out on Sunday. As a rule, we recite Retzei by Shalosh Sedudos even when the meal is continued after Shabbos. The only exception to this rule is if Maariv is Davened before reciting Birchas Hamazon. One cannot recite Retzei once Shabbos has ended with the prayer of Ata Chonantanu in Maariv.

According to the first opinion in the Mishna Berura, only Retzei should be recited, as it is contradictory to recite both Reztei and Yaaleh Viyavo, as it cannot be Shabbos and Rosh Chodesh at the same time. According to the second opinion in the Mishna Berura, one can add Yaaleh Viyavo, as we are not concerned with this apparent contradiction.

Reb Shlomo Gantzfreid in the Kitzur Shulchan Aruch writes that one should avoid eating a Zayis of bread after nightfall. This is in order to avoid dealing with this dilemma. Reb Shlomo Zalaman Aurbach rules that although one should avoid eating after nightfall, it is permissible to eat products other than bread. It is also permissible to eat bread, as long as one avoids eating the proper amount necessary in order to recite Birchas Hamazon after night begins.

Halacha Orach Chaim 188

In our last post we discussed when it is too late to insert the Bracha in place of Retzei and Yaaleh Viyavo. It is important to note that Benching is only repeated on Yom Tov. On Rosh Chodesh and Chol Hamoed, once the time for reciting the Bracha in place of Yaaleh Viyavo has passed, Birchas Hamazon should be completed, and it is not repeated. The reason for this is because there is no obligation to eat a meal on those days. It is therefore not necessary to repeat Benching.

Based on this reasoning, Rebbi Akiva Eiger rules regarding women that forget to recite Retzei on Shabbos, and Yaaleh Viyavo on the first night of Pesach, that they are required to repeat Benching. This is because women are obligated to eat bread or Matzah at those times. However, on all other Yomim Tovim they would not repeat Benching if it is omitted.

Kaf Hachaim makes a fascinating point regarding this Halacha. We learned earlier that there is a discussion if Birchas Hamazon is an obligation for women based on a Torah law, or Rabbinic law. Since Benching itself is not clearly a Torah obligation for women, even on Shabbos and the first night of Pesach, they would not repeat Birchas Hamazon.

It is interesting to note, that Rebbi Akiva Eiger brought by the Mishna Berura 186, 3, rules that women do not repeat Birchas Hamazon if they are in doubt if it was recited. Here, Rebbi Akiva Eiger requires women to repeat Birchas Hamazon if Retzei is omitted. Obviously the obligation to repeat Retzei is based on whether or not there is an obligation to eat, and it has nothing to do with the nature of Birchas Hamazon being a Torah or Rabbinic obligation. This is not like the Kaf Hachaim.

Halacha Orach Chaim 188

If someone forgot to recite Retzei on Shabbos, or Yaaleh Veyavo on Yom Tov, the Mechaber in 188, 6 bring the proper Bracha that should be recited, on condition that the fourth Bracha of Hatov Vhameitiv was not started.

If someone is not sure if Retzei or Yaaleh Veyavo was recited, he must assume that it was omitted.

There is a discussion among the commentaries when we consider the fourth Bracha started. The Mishna Berura writes that if he just said Baruch Atah Hashem, he should conclude Lamdeini Chuckecha, and recite the appropriate Bracha in place of Retzei or Yalaleh Veyavo before continuing with the fourth Bracha of Benching.

If he already said the words Melech Haolom, and at that point remembered Retzei, the Halacha according to the Mishna Berura is that he should complete the Nusach of the Bracha that comes in place of Retzei. In the Biur Halacha, the Chofetz Chaim question how one can complete this Bracha in place of Hatov Vhameitiv, as he already removed himself from the third Bracha of Benching. Although the Chofetz Chaim does not resolve this issue, in the Mishna Berura he seems to accept the option of concluding with the Bracha for Shabbos or Yom Tov. Reb Shlomo Zalman Aurbach comments that this is the accepted custom.

Once the words Hatov Vhameitiv are recited, Birchas Hamazon must be repeated from the beginning.

Halacha Orach Chaim 188

After concluding the Bracha Bonei Berachamav Yerushalayim, Amen is said. The reason for this is to show that this concludes Birchas Hamazon Deoreisa. The Rama says that it should be said softly so that the next Bracha is not viewed as unimportant. However, when Benching with a Mezuman, one should say it out loud.

When reciting the Amen, a short pause should be made before concluding it. The reason for this is to show that the Amen is not part of the Bracha. The Mishna Berura points out in 124,34, that one should not delay too long, or else the Amen cannot be recited, as it will be considered an Amen Yesomeh. We learned about Amen Yesomah earlier.

Since this Bracha is a prayer for mercy and not thanks, like the second Bracha is, Yaaleh Veyavo and Retzei are added during this Bracha on Shabbos and Rosh Chodesh. The addition that comes more often is first, therefore Retzei is recited before Yaaleh Viyavo on Shabbos Rosh Chodesh.

It is interesting to note that the Shagas Aryeh rules that someone who erroneously began Yaaleh Viyavo on Shabbos Rosh Chodesh, should interrupt to recite Retzei, and then go back to Yaaleh Viyavo from the beginning.