Siman 379

The sages ordained to add for a mourner in Birkat HaMazon, in the blessing of "HaTov VeHaMeitiv," a mention of the event. Specifically, when he reaches "He did good, He does good, He will do good for us," he should say: True God, True Judge, Who judges with righteousness, Who takes souls with justice, Who rules in His world to do in it according to His will. For all His ways are justice, and we are His people and His servants, and in everything we are obligated to thank Him and bless Him. He Who fences the breach of Israel, He shall fence this breach from us and from this mourner for life and for peace. He has rewarded us, He rewards us, He will reward us forever, with grace and with kindness etc. forever may He not let us lack. May the Merciful One etc.

And some add in the third blessing, when he reaches "and build Jerusalem," he should say: And build Jerusalem the holy city speedily in our days. Comfort, Hashem our G-d, the mourners of Jerusalem. And the mourners who are mourning in this mourning, comfort them from their mourning, and gladden them from their sorrow, as it is said: "As a man whom his mother comforts, so will I comfort you." Blessed are You, Hashem, Who comforts Zion with the building of Jerusalem. Amen. And he should not say "Who comforts mourners and builds Jerusalem," for one does not conclude a blessing with two matters. However, "Who comforts Zion and builds Jerusalem" he may conclude, just as we conclude on Tisha B'Av at Mincha, for it is a single matter (Shach, subsection 4). And although this was not mentioned in Berakhot (Berakhot 46b), it can be said that it is not an absolute requirement, for our sages, of blessed memory, only commanded to mention the nature of the occasion. And if there is a cup of blessing, the mourner should recite the blessing, for he sits at the head, as I wrote at the beginning of siman 376. And some say that in the blessing of zimun one must say: "Let us bless the Comforter of mourners of whose food we have eaten." And they say: "Blessed is the Comforter etc.," and the one reciting the blessing repeats this. And if there are ten, he should say: "Let us bless our G-d, the Comforter etc.," and they answer accordingly, and he repeats accordingly.

The Tur wrote in the name of a Gaon that this blessing must be recited whether one blesses alone, whether among three, or whether among ten. And that which was explained in the Gemara that the blessing of mourners requires ten specifically—this refers to the blessing of the open area and the row that existed in the time of the Shas, and not nowadays when we do not have these blessings. However, the blessing of mourners in the birkat hamazon, namely the addition that was explained, is even for an individual. And so it is implied from all the poskim that this blessing is even for an individual. And in the Mordechai (chapter "Elu Megalchin") he wrote that such is the opinion of the Semag, and that our teacher, Isaac, found such in a responsa of the Geonim. And only the opinion of our teacher, Meir, is that this blessing also requires ten. And since this is only a minority opinion—we do not rule like him. And even the individual is obligated in this blessing, and those who are lenient in this do not act properly. And a mourner joins to the ten.

During all seven days one adds this blessing, except on Shabbat when blessing with others—one does not add this blessing as it is like a public display. But if the mourner eats alone, or even if many eat but all of them are mourners—they bless, as it is like a private matter and applies on Shabbat. The mourner joins for prayer and for zimun, whether for three or for ten. And there is one who says that during the first meal, which is the seudat havra'ah—the mourner does not join for zimun (see Shach subsection 6).