Level 4 — Daat HaRav (Alter Rebbe) — Siman קצ״ז · דִּינֵי צֵרוּף לְזִמּוּן שְׁלֹשָׁה אוֹ עֲשָׂרָה

דִּין צֵרוּף לְזִמּוּן שְׁלֹשָׁה אוֹ עֲשָׂרָה, וּבוֹ ט׳ סְעִיפִים:
שְׁנַיִם שֶׁאָכְלוּ כְּאַחַת וְגָמְרוּ סְעוּדָתָם וּבָא שְׁלִישִׁי וְקָבַע אֶצְלָם, אִם אֵינָם שְׂבֵעִים כָּל כָּךְ בְּעִנְיָן שֶׁאִם הָיוּ מְבִיאִים לִפְנֵיהֶם אֵיזֶה דָּבָר הֶחָבִיב אֶצְלָם לְקִנּוּחַ סְעוּדָה הָיוּ יְכוֹלִים לֶאֱכֹל מִמֶּנָּה אֲפִלּוּ כָּל שֶׁהוּא — לֹא נִגְמְרָה סְעוּדָתָם עֲדַיִן וּמִצְטָרֵף עִמָּהֶם, אַף עַל פִּי שֶׁלֹּא אָכְלוּ כְּלוּם מִשֶּׁבָּא אֶצְלָם.
וְאִם אָמְרוּ כְּבָר "נְבָרֵךְ בִּרְכַּת הַמָּזוֹן" — הֲרֵי הִסִּיחוּ דַּעְתָּם מִלֶּאֱכֹל עוֹד, וְנִגְמְרָה סְעוּדָתָם, וְשׁוּב אֵינוֹ מִצְטָרֵף עִמָּהֶם, אֶלָּא אִם כֵּן אָכְלוּ עִמּוֹ.
(וְאֵין צָרִיךְ לוֹמַר אִם הִסִּיחוּ דַּעְתָּם בְּפֵרוּשׁ מִלֶּאֱכֹל עוֹד. וְאַף לְהָאוֹמְרִים שֶׁהֶסַּח הַדַּעַת מֵאֲכִילָה אֵינוֹ זָקוּק לַחֲזֹר לְבָרֵךְ "הַמּוֹצִיא" אִם נִמְלַךְ לַחֲזֹר וְלֶאֱכֹל, מִפְּנֵי שֶׁדַּרְכּוֹ שֶׁל אָדָם לִהְיוֹת נִמְלָךְ בִּסְעוּדָתוֹ לְהִמָּשֵׁךְ מִסְּעוּדָה קְטַנָּה לִגְדוֹלָה, מִכָּל מָקוֹם כָּל זְמַן שֶׁאֵינוֹ נִמְלַךְ וְחוֹזֵר וְאוֹכֵל — נִגְמְרָה אֲכִילָה הָרִאשׁוֹנָה בְּהֶסַּח דַּעְתּוֹ, כֵּיוָן שֶׁעוֹמֵד בְּדַעְתּוֹ וְאֵינוֹ חוֹזֵר מִמֶּנָּה [)].
וּמִכָּל מָקוֹם, אֲפִלּוּ נָטְלוּ יְדֵיהֶם מַיִם אַחֲרוֹנִים — מִצְוָה שֶׁיַּחְזְרוּ וְיִטְּלוּ מַיִם רִאשׁוֹנִים וִיבָרְכוּ "הַמּוֹצִיא" וְיֹאכְלוּ כְּזַיִת כְּדֵי לְבָרֵךְ בְּזִמּוּן. וַאֲפִלּוּ אִם זֶה אֵינוֹ חָפֵץ לֶאֱכֹל כְּלָל — מִצְוָה שֶׁיִּתְּנוּ לוֹ לֶאֱכֹל מְעַט כְּדֵי לְזַמֵּן עָלָיו, שֶׁכָּל שְׁנַיִם שֶׁאָכְלוּ כְּאֶחָד מִצְוָה עֲלֵיהֶם לְחַזֵּר אַחַר זִמּוּן כָּל מַה שֶּׁיְּכוֹלִים, כְּמוֹ שֶׁנִּתְבָּאֵר בְּסִימָן קצ״ג:

The law of joining a zimun of three or of ten, and it comprises nine seifim. Two who ate together and finished their meal, and a third came and settled beside them: if they are not so satiated — that is, if some dish dear to them were brought before them at the close of the meal they would still be able to eat of it, even the smallest amount — their meal is not yet finished and he joins with them, even though they ate nothing from the time he came to them.
But if they already said “nevarekh birkat hamazon” — behold they have turned their mind away from eating further, their meal is finished, and he no longer joins with them, unless they eat with him.
(And it goes without saying that this is so if they explicitly turned their mind away from eating further. And even according to those who say that turning one’s mind away from food does not require repeating “hamotzi” if he changes his mind and eats again — since it is a person’s way to change his mind during his meal and extend from a small meal into a large one — nevertheless, so long as he does not change his mind and eat again, the first eating was concluded by his turning his mind away, since he stands by his decision and does not retract it.)
And in any case, even if they have already washed mayim aḥaronim — it is a mitzvah that they go back and wash mayim rishonim, bless “hamotzi” and eat a kazayit, in order to bless with zimun. And even if this one does not wish to eat at all — it is a mitzvah that they give him a little to eat so as to make the zimun upon him; for any two who ate together have the mitzvah to pursue zimun as much as they can, as was explained in siman 193.

אֵין מְזַמְּנִין אֶלָּא עַל מִי שֶׁאָכַל כְּזַיִת, שֶׁפָּחוֹת מִכְּזַיִת אֵינוֹ נִקְרָא אֲכִילָה, וַאֲפִלּוּ אָכַל פַּת.
וּמִשֶּׁאָכַל כְּזַיִת מְזַמְּנִין עָלָיו, וּמִצְטָרֵף בֵּין לִשְׁלֹשָׁה בֵּין לַעֲשָׂרָה, אֲפִלּוּ אָכַל כְּזַיִת יָרָק אוֹ שְׁאָר פֵּרוֹת. וַאֲפִלּוּ אֵין כְּזַיִת בַּיָּרָק, אֶלָּא שֶׁטִּבְּלוֹ בְּצִיר וְאָכַל וְיֵשׁ בּוֹ כְּזַיִת עִם הַצִּיר שֶׁעַל גַּבֵּי הַזַּיִת — מְזַמְּנִין עָלָיו, שֶׁהַצִּיר מִצְטָרֵף, כְּמוֹ שֶׁיִּתְבָּאֵר בְּסִימָן ר״י.
וַאֲפִלּוּ לֹא אָכַל כְּלוּם אֶלָּא שָׁתָה רְבִיעִית מֵאֵיזֶה מַשְׁקֶה, וַאֲפִלּוּ מִן הַמַּיִם — מִצְטָרֵף עִמָּהֶם וְעוֹנֶה: "בָּרוּךְ שֶׁאָכַלְנוּ", שֶׁשְּׁתִיָּה בִּכְלַל אֲכִילָה.
וְהוּא שֶׁאָכַל כְּזַיִת זֶה אוֹ שָׁתָה רְבִיעִית זוֹ לְאַחַר שֶׁעָלָה וְהֵסֵב עִמָּהֶם עַל הַמִּטָּה בִּימֵי חַכְמֵי הַתַּלְמוּד, שֶׁכָּךְ הָיְתָה דֶּרֶךְ קְבִיעוּת סְעוּדָתָם, וּבַזְּמַן הַזֶּה בִּישִׁיבָה בְּשֻׁלְחָן אֶחָד, שֶׁאִם לֹא כֵּן אַף מִי שֶׁאוֹכֵל פַּת אֵינוֹ מִצְטָרֵף, כְּמוֹ שֶׁנִּתְבָּאֵר בְּסִימָן קצ״ג. וּמִכָּל מָקוֹם, אֵין צָרִיךְ לֵישֵׁב אֶלָּא בִּשְׁעַת אֲכִילָתוֹ אוֹ שְׁתִיָּתוֹ, אֲבָל בִּשְׁעַת הַזִּמּוּן יְכוֹלִים לְזַמֵּן עָלָיו אֲפִלּוּ עוֹמֵד בַּחוּץ לִפְנֵי הַפֶּתַח, כְּמוֹ שֶׁנִּתְבָּאֵר בְּסִימָן קצ״ד.
וַאֲפִלּוּ שְׁלֹשָׁה שֶׁאָכְלוּ יָרָק אוֹ שָׁתוּ מִצְטָרְפִים לְשִׁבְעָה שֶׁאָכְלוּ פַּת לְזַמֵּן בְּשֵׁם, הוֹאִיל וְרֹב הַנִּכָּר הוּא מֵאוֹכְלֵי פַּת. אֲבָל שִׁשָּׁה שֶׁאָכְלוּ פַּת — אֵין מְזַמְּנִין בְּשֵׁם בְּצֵרוּף אַרְבָּעָה שֶׁלֹּא אָכְלוּ פַּת, שֶׁשִּׁשָּׁה אֵינָם רֹב הַנִּכָּר.
וְיֵשׁ אוֹמְרִים שֶׁלֹּא הֵקֵלּוּ בַּאֲכִילַת יָרָק אוֹ שְׁאָר אֳכָלִים חוּץ מִן הַפַּת וּבִשְׁתִיַּת כָּל מַשְׁקֶה, אֶלָּא לְהִצְטָרֵף לַעֲשָׂרָה, שֶׁכְּבָר יֵשׁ מֵאוֹכְלֵי הַפַּת שִׁעוּר הָרָאוּי לְזִמּוּן, אֶלָּא שֶׁאֵינָן רַשָּׁאִין לְהַזְכִּיר הַשֵּׁם בְּפָחוֹת מֵעֲשָׂרָה, לָכֵן דַּי בְּצֵרוּף שְׁלֹשָׁה אוֹכְלֵי יָרָק, אוֹ שׁוֹתִים אֵיזֶה מַשְׁקֶה, שֶׁהֵם יְכוֹלִים גַּם כֵּן לַעֲנוֹת עִמָּהֶם: "בָּרוּךְ אֱלֹהֵינוּ שֶׁאָכַלְנוּ מִשֶּׁלּוֹ", אֲבָל בְּזִמּוּן שְׁלֹשָׁה, כָּל שֶׁאֵין שְׁלֹשָׁה שֶׁאָכְלוּ פַּת שֶׁהֵם חַיָּבִים בְּזִמּוּן — אֵין מְזַמְּנִין בְּצֵרוּף מִי שֶׁלֹּא אָכַל פַּת, כֵּיוָן שֶׁאֵינוֹ חַיָּב בְּזִמּוּן.
וְיֵשׁ לָחֹשׁ לְדִבְרֵיהֶם לְכַתְּחִלָּה, שֶׁאִם אָכְלוּ שְׁנַיִם וּבָא שְׁלִישִׁי אֶצְלָם וִיכוֹלִים לְהַזְקִיקוֹ שֶׁיֹּאכַל כְּזַיִת פַּת — יִתְּנוּ לוֹ פַּת. אֲבָל אִם אֵינוֹ רוֹצֶה — נוֹהֲגִין לִתֵּן לוֹ לִשְׁתּוֹת, אוֹ לֶאֱכֹל מִינֵי מְגָדִים, וּמְזַמְּנִים עָלָיו, כַּסְּבָרָא הָרִאשׁוֹנָה:

We make the zimun only upon one who ate a kazayit, for less than a kazayit is not called eating — and this even if he ate bread.
Once he has eaten a kazayit we make the zimun upon him, and he joins both for three and for ten, even if he ate only a kazayit of vegetable or of other fruits. And even if there is no kazayit in the vegetable, but he dipped it in brine and ate it, and there is a kazayit together with the brine that is upon the vegetable — we make the zimun upon him, for the brine joins the measure, as will be explained in siman 210.
And even if he ate nothing at all but drank a reviit of any beverage, and even of water — he joins with them and answers: “barukh she’akhalnu,” for drinking is included in eating.
And this provided that he ate that kazayit or drank that reviit after he had come up and reclined with them upon the couch, in the days of the Sages of the Talmud, for such was the manner in which their meal was fixed; and nowadays, by sitting at one table. For otherwise even one who eats bread does not join, as was explained in siman 193. Nevertheless, he need only be seated at the time of his eating or his drinking; but at the time of the zimun they may make the zimun upon him even if he stands outside before the doorway, as was explained in siman 194.
And even three who ate vegetable or who drank join with seven who ate bread to make the zimun with the Name, since the manifest majority is of those who eat bread. But six who ate bread — we do not make the zimun with the Name by joining to them four who did not eat bread, for six are not a manifest majority.
And there are those who say that this leniency regarding eating vegetable or other foods besides bread, and regarding drinking any beverage, was granted only for joining to ten — for among the bread-eaters there is already the measure fit for zimun, only that they may not mention the Name with fewer than ten; therefore it suffices to join three who eat vegetable, or who drink some beverage, since they too can answer with them: “barukh Elokenu she’akhalnu mishelo.” But for a zimun of three, so long as there are not three who ate bread and who are obligated in zimun — we do not make the zimun by joining one who did not eat bread, since he is not obligated in zimun.
And one should take their words into account lekhatḥilah: if two ate and a third came to them, and they can prevail upon him to eat a kazayit of bread — let them give him bread. But if he does not wish to — the practice is to give him something to drink, or choice delicacies to eat, and we make the zimun upon him, according to the first opinion.

וְכָל זֶה לְעִנְיַן צֵרוּף, אֲבָל שְׁלֹשָׁה אוֹכְלֵי פַּת שֶׁמְּזַמְּנִים לְדִבְרֵי הַכֹּל — יָכוֹל לַעֲנוֹת עִמָּהֶם אַף מִי שֶׁאָכַל כְּזַיִת יָרָק אוֹ שָׁתָה רְבִיעִית, וַאֲפִלּוּ שֶׁלֹּא בִּישִׁיבָה בַּשֻּׁלְחָן עִמָּהֶם, כְּמוֹ שֶׁיִּתְבָּאֵר בְּסִימָן קצ״ח:

And all of this concerns joining; but where three bread-eaters make the zimun according to all opinions — even one who ate a kazayit of vegetable or drank a reviit may answer with them, and even without sitting at the table with them, as will be explained in siman 198.

הַמִּצְטָרֵף צָרִיךְ לִזָּהֵר שֶׁלֹּא לְבָרֵךְ בְּרָכָה אַחֲרוֹנָה עַד שֶׁיְּזַמְּנוּ עָלָיו, שֶׁאִם בֵּרַךְ בְּרָכָה אַחֲרוֹנָה עַל אֲכִילָתוֹ אוֹ שְׁתִיָּתוֹ — שׁוּב אֵינוֹ יָכוֹל לְזַמֵּן וְלַעֲנוֹת עִמָּהֶם, שֶׁכְּבָר נִסְתַּלֵּק מֵהֶם:

The one who joins must take care not to say the final blessing before they make the zimun upon him; for if he said the final blessing over his eating or his drinking — he can no longer make the zimun or answer with them, since he has already withdrawn from them.

עַד הֵיכָן הוּא הַזִּמּוּן? עַד סִיּוּם בִּרְכַּת "הַזָּן", שֶׁכָּל הַמִּצְטָרְפִים לַזִּמּוּן צְרִיכִים לְכַוֵּן וְלִשְׁמֹעַ בְּרָכָה רִאשׁוֹנָה מִבִּרְכַּת הַמָּזוֹן מִפִּי הַמְזַמֵּן, כְּמוֹ שֶׁנִּתְבָּאֵר בְּסִימָן קצ״ג. וְאַף עַל פִּי שֶׁשָּׁמַע בִּרְכַּת "הַזָּן", לֹא נִפְטַר בָּהּ מִבְּרָכָה אַחֲרוֹנָה עַל אֲכִילָתוֹ, אֶלָּא אִם כֵּן אָכַל תְּמָרִים, וּבִשְׁתִיָּה לֹא נִפְטַר אֶלָּא אִם כֵּן שָׁתָה יַיִן, כְּמוֹ שֶׁיִּתְבָּאֵר בְּסִימָן ר״ח. וּמִכָּל מָקוֹם, לְכַתְּחִלָּה יְכַוֵּן שֶׁלֹּא לָצֵאת יְדֵי חוֹבָתוֹ לְכַתְּחִלָּה בִּשְׁמִיעָתוֹ בִּרְכַּת הַמָּזוֹן, שֶׁלְּכַתְּחִלָּה צָרִיךְ לְבָרֵךְ עַל כָּל מִין בְּרָכָה הָרְאוּיָה לוֹ, כְּמוֹ שֶׁיִּתְבָּאֵר:

How far does the zimun extend? Until the conclusion of the blessing “hazan.” For all who join the zimun must have intent and listen to the first blessing of birkat hamazon from the mouth of the mezamen, as was explained in siman 193. And although he heard the blessing “hazan,” he was not thereby discharged of the final blessing due for his eating, unless he ate dates; and as for drinking, he is discharged only if he drank wine, as will be explained in siman 208. Nevertheless, lekhatḥilah he should intend not to discharge his obligation at the outset by hearing birkat hamazon, for lekhatḥilah one must recite over each kind the blessing befitting it, as will be explained.

שְׁנַיִם שֶׁאָכְלוּ וְשָׂבְעוּ וְנָתְנוּ לִשְׁלִישִׁי לֶאֱכֹל מְעַט שֶׁיִּצְטָרֵף עִמָּהֶם לְזִמּוּן, אִם אָכַל כְּזַיִת פַּת — יָכוֹל לְבָרֵךְ לָהֶם בִּרְכַּת הַמָּזוֹן, אֲפִלּוּ לֹא אָכַל כְּדֵי שְׂבִיעָה וְאֵינוֹ חַיָּב בְּבִרְכַּת הַמָּזוֹן מִן הַתּוֹרָה כְּמוֹתָם, לְפִי שֶׁמִּן הַתּוֹרָה אַף מִי שֶׁלֹּא אָכַל כְּלָל יָכוֹל לְהוֹצִיא אֶת מִי שֶׁאָכַל וְשָׂבַע, שֶׁלֹּא אָמְרוּ: כָּל מִי שֶׁאֵינוֹ מְחֻיָּב בַּדָּבָר אֵינוֹ מוֹצִיא אֲחֵרִים יְדֵי חוֹבָתָם, אֶלָּא בְּמִי שֶׁאֵינוֹ מְצֻוֶּה כְּלָל, כְּמוֹ נָשִׁים בְּמִצְוֹת שֶׁאֵינָן נוֹהֲגוֹת בָּהֶן, אֲבָל כָּל שֶׁמִּצְוָה זוֹ נוֹהֶגֶת בָּהֶן, אַף עַל פִּי שֶׁלֹּא נִתְחַיֵּב בָּהּ עַתָּה הוּא אֶלָּא חֲבֵרוֹ — נִקְרָא הוּא גַּם כֵּן מְחֻיָּב בַּדָּבָר מִדִּין עֲרֵבוּת, שֶׁכָּל יִשְׂרָאֵל עֲרֵבִים זֶה בָּזֶה, וְעָלָיו לְהַצִּיל חֲבֵרוֹ מֵעָוֹן, וּלְפָטְרוֹ מִמִּצְוָה שֶׁנִּתְחַיֵּב בָּהּ.
וְאַף שֶׁבִּרְכַּת הַמָּזוֹן הִיא בִּרְכַּת הַנֶּהֱנִין, וּבְבִרְכַּת הַנֶּהֱנִין מִי שֶׁאֵינוֹ נֶהֱנָה אֵינוֹ מוֹצִיא אֶת מִי שֶׁנֶּהֱנָה, לְפִי שֶׁאֵינוֹ מְחֻיָּב בִּבְרָכָה זוֹ מִשּׁוּם עֲרֵבוּת הוֹאִיל וְאֵינוֹ חוֹבָה עַל חֲבֵרוֹ, שֶׁיָּכוֹל הוּא שֶׁלֹּא לֵהָנוֹת וְשֶׁלֹּא לְהִתְחַיֵּב בִּבְרָכָה, כְּמוֹ שֶׁנִּתְבָּאֵר בְּסִימָן קס״ז, מִכָּל מָקוֹם, בְּבִרְכַּת הַמָּזוֹן כֵּיוָן שֶׁכְּבָר נֶהֱנָה וְנִתְחַיֵּב לְבָרֵךְ — מְחֻיָּב הוּא לְהַצִּילוֹ מֵעָוֹן וּלְבָרֵךְ לוֹ.
אֶלָּא שֶׁהַחֲכָמִים אָמְרוּ, שֶׁמִּי שֶׁלֹּא אָכַל פַּת אֵינוֹ יָכוֹל לְבָרֵךְ בִּרְכַּת הַמָּזוֹן, שֶׁאֵין לְבָרֵךְ בִּרְכַּת הַנֶּהֱנִין בְּלֹא הֲנָאָה, וְסָמְכוּ זֶה עַל מַה שֶּׁכָּתוּב: "וְאָכַלְתָּ וְשָׂבָעְתָּ וּבֵרַכְתָּ", מִי שֶׁאָכַל הוּא יְבָרֵךְ. וַאֲפִלּוּ אִם זֶה שֶׁאָכַל וְשָׂבַע אֵינוֹ יוֹדֵעַ לְבָרֵךְ — אֵין חֲבֵרוֹ מְבָרֵךְ לוֹ, שֶׁיֵּשׁ כֹּחַ בְּיַד חֲכָמִים לַעֲקֹר דָּבָר מִן הַתּוֹרָה בְּשֵׁב וְאַל תַּעֲשֶׂה, וְעוֹד שֶׁזֶּה אֵינָהּ עֲקִירָה, שֶׁיָּכוֹל אַחֵר לֶאֱכֹל עִמּוֹ וּלְבָרֵךְ לוֹ. אֲבָל מִי שֶׁאָכַל פַּת אֲפִלּוּ כְּזַיִת, כֵּיוָן שֶׁמְּבָרֵךְ עַל הֲנָאַת עַצְמוֹ — מוֹצִיא גַּם כֵּן חֲבֵרוֹ שֶׁאָכַל כְּדֵי שְׂבִיעָה.
אֲבָל אִם לֹא אָכַל כְּזַיִת פַּת שֶׁמְּבָרְכִין אַחֲרָיו בִּרְכַּת הַמָּזוֹן, אֲפִלּוּ אָכַל תַּבְשִׁיל מֵחֲמֵשֶׁת הַמִּינִים שֶׁמְּבָרְכִין אַחֲרָיו מֵעֵין שָׁלֹשׁ — אֵינוֹ יָכוֹל לְבָרֵךְ בִּרְכַּת הַמָּזוֹן כְּדֵי לְהוֹצִיא אֶת הָאוֹכְלִים פַּת, אֲפִלּוּ לֹא אָכְלוּ אֶלָּא כְּזַיִת.
וְיֵשׁ אוֹמְרִים שֶׁמִּי שֶׁלֹּא אָכַל כְּדֵי שְׂבִיעָה אֵינוֹ מוֹצִיא אֶת מִי שֶׁאָכַל כְּדֵי שְׂבִיעָה. וְטוֹב לָחֹשׁ לְדִבְרֵיהֶם לְכַתְּחִלָּה, שֶׁאִם בְּנֵי חֲבוּרָה מִקְצָתָם אָכְלוּ כְּדֵי שְׂבִיעָה וּמִקְצָתָם לֹא אָכְלוּ כְּדֵי שְׂבִיעָה — מְבָרֵךְ אֶחָד מֵהָאוֹכְלִים כְּדֵי שְׂבִיעָה וְיוֹצְאִים הָאֲחֵרִים. אֶלָּא אִם כֵּן שֶׁהָאוֹכְלִים כְּדֵי שְׂבִיעָה אֵין בָּהֶם מִי שֶׁיּוֹדֵעַ לְבָרֵךְ — אֲזַי יְבָרֵךְ מִי שֶׁאָכַל כְּזַיִת וְיוֹצִיא אֶת כֻּלָּם יְדֵי חוֹבָתָם (אִם הָיָה שָׂבֵעַ כְּבָר קֹדֶם שֶׁאָכַל הַכְּזַיִת, שֶׁאִי אֶפְשָׁר לוֹ לְהָבִיא עַצְמוֹ לִידֵי חִיּוּב שֶׁל תּוֹרָה עַל יְדֵי שֶׁיֹּאכַל יוֹתֵר. אֲבָל אִם אֶפְשָׁר לוֹ לֶאֱכֹל יוֹתֵר — יֵשׁ לָחֹשׁ לַסְּבָרָא הָאַחֲרוֹנָה):

Two who ate and were satiated, and who gave a third a little to eat so that he would join with them for zimun: if he ate a kazayit of bread — he may say birkat hamazon for them, even though he did not eat his fill and is not obligated in birkat hamazon by Torah law as they are. For by Torah law even one who ate nothing at all may discharge one who ate and was satiated: they said “whoever is not obligated in a matter cannot discharge others of their obligation” only of one who is not commanded in it at all — like women in mitzvot that do not apply to them; but wherever this mitzvah does apply to them, even though he is not obligated in it now but his fellow is — he too is called “obligated in the matter,” by the law of arevut, for all Israel are guarantors one for another, and it falls upon him to save his fellow from transgression and to discharge him of a mitzvah in which he is obligated.
And although birkat hamazon is a birkat hanehenin, and in blessings over enjoyment one who does not enjoy cannot discharge one who does enjoy — because he is not obligated in that blessing on account of arevut, since it is no obligation upon his fellow, who could refrain from enjoying and from becoming liable to the blessing, as was explained in siman 167 — nevertheless, with birkat hamazon, since he has already enjoyed and become liable to bless, he is obligated to save him from transgression and to bless for him.
Only that the Sages said that one who did not eat bread cannot say birkat hamazon, for one does not recite a blessing over enjoyment without enjoyment; and they rested this upon what is written: “ve’akhalta vesavata uverakhta” — the one who ate is the one who shall bless. And even if the one who ate and was satiated does not know how to bless — his fellow does not bless for him, for the Sages have the power to uproot a matter of Torah law by passivity; and moreover this is no uprooting, since another can eat with him and bless for him. But one who ate bread, even a kazayit, since he blesses over his own enjoyment — he also discharges his fellow who ate his fill.
But if he did not eat a kazayit of bread, after which birkat hamazon is said — even if he ate a cooked dish of the five species, after which me’ein shalosh is said — he cannot say birkat hamazon in order to discharge those who eat bread, even if they ate only a kazayit.
And there are those who say that one who did not eat his fill does not discharge one who ate his fill. And it is good to take their words into account lekhatḥilah: if among the members of a company some ate their fill and some did not eat their fill — let one of those who ate his fill bless, and the others are discharged. Unless among those who ate their fill there is none who knows how to bless — then let the one who ate a kazayit bless and discharge them all of their obligation (if he was already satiated before he ate the kazayit, so that it is impossible for him to bring himself to a Torah obligation by eating more; but if it is possible for him to eat more — one should take the latter opinion into account).

וְאִם אָכְלוּ כֻּלָּם כְּדֵי שְׂבִיעָה, וּמִקְצָתָם שָׁתוּ וּמִקְצָתָם לֹא שָׁתוּ וְהֵם תְּאֵבִים לִשְׁתּוֹת — טוֹב שֶׁיְּבָרֵךְ מִי שֶׁשָּׁתָה, לְפִי שֶׁיֵּשׁ אוֹמְרִים שֶׁמִּן הַתּוֹרָה אֵינוֹ חַיָּב לְבָרֵךְ אֶלָּא אִם שָׁתָה אִם הוּא תָּאֵב לִשְׁתּוֹת, שֶׁנֶּאֱמַר "וְאָכַלְתָּ וְשָׂבָעְתָּ", וְדָרְשׁוּ חֲכָמִים: "וְאָכַלְתָּ" — זוֹ אֲכִילָה, "וְשָׂבָעְתָּ" — זוֹ שְׁתִיָּה.
וְאַף עַל פִּי שֶׁאֵין דִּבְרֵיהֶם עִקָּר, שֶׁזֶּה סֶמֶךְ בְּעָלְמָא הוּא שֶׁסָּמְכוּ חֲכָמִים לְחַיֵּב בִּרְכַּת הַמָּזוֹן עַל כְּזַיִת, שֶׁנֶּאֱמַר "וְאָכַלְתָּ" — זוֹ אֲכִילָה, וַאֲכִילָה בִּכְזַיִת, "וְשָׂבָעְתָּ" — זוֹ שְׁתִיָּה, אֲבָל אֵין הַמִּקְרָא יוֹצֵא מִידֵי פְּשׁוּטוֹ, שֶׁאֵינוֹ חַיָּב לְבָרֵךְ אֶלָּא כְּשֶׁאָכַל וְשָׂבַע וַאֲפִלּוּ לֹא שָׁתָה, מִכָּל מָקוֹם טוֹב לָחֹשׁ לְדִבְרֵיהֶם בְּמָקוֹם שֶׁאֶפְשָׁר, שֶׁיְּבָרֵךְ מִי שֶׁשָּׁתָה.
אֲבָל אִם מִקְצָתָם אָכְלוּ לָשֹׂבַע וְלֹא שָׁתוּ וּמִקְצָתָם לֹא אָכְלוּ לָשֹׂבַע וְשָׁתוּ — יְבָרֵךְ מִי שֶׁאָכַל לָשֹׂבַע אַף עַל פִּי שֶׁלֹּא שָׁתָה, כֵּיוָן שֶׁהָעִקָּר כְּהָאוֹמְרִים שֶׁחִיּוּב בִּרְכַּת הַמָּזוֹן מִן הַתּוֹרָה תָּלוּי בַּאֲכִילָה כְּדֵי שְׂבִיעָה וְלֹא בִּשְׁתִיָּה:

And if they all ate their fill, and some drank and some did not drink while they are thirsty to drink — it is good that the one who drank should bless, since there are those who say that by Torah law he is obligated to bless only if he drank, where he is thirsty to drink; for it is said “ve’akhalta vesavata,” and the Sages expounded: “ve’akhalta” — this is eating; “vesavata” — this is drinking.
And although their words are not the essential view — for this is a mere support upon which the Sages rested the obligation of birkat hamazon from a kazayit, as it is said “ve’akhalta” — this is eating, and eating is a kazayit; “vesavata” — this is drinking; yet the verse does not depart from its plain sense, according to which he is obligated to bless only when he ate and was satiated, even if he did not drink — nevertheless it is good to take their words into account where possible, that the one who drank should bless.
But if some ate to satiety and did not drink, and some did not eat to satiety but drank — let the one who ate to satiety bless, even though he did not drink, since the essential view is like those who say that the Torah obligation of birkat hamazon depends on eating one’s fill and not on drinking.

וְכָל זֶה כְּשֶׁמְּבָרְכִים בְּזִמּוּן כְּתִקּוּן חֲכָמִים, שֶׁהַמְזַמֵּן לְבַד הוּא מְבָרֵךְ וּמוֹצִיא אֶת כֻּלָּם יְדֵי חוֹבָתָם. אֲבָל עַכְשָׁו שֶׁכֻּלָּם מְבָרְכִים בְּלַחַשׁ עִם הַמְזַמֵּן — אֵין לָחֹשׁ לְכָל זֶה, וְיָכוֹל לְבָרֵךְ אַף מִי שֶׁאָכַל כְּזַיִת לְבַד וְלֹא שָׁתָה, אַף עַל פִּי שֶׁיֵּשׁ אֲחֵרִים שֶׁאָכְלוּ לָשֹׂבַע וְשָׁתוּ.
אֶלָּא שֶׁכְּבָר נִתְבָּאֵר בְּסִימָן קפ״ג שֶׁאֵין לִנְהֹג כֵּן, אֶלָּא יִשְׁמְעוּ מִפִּי הַמְזַמֵּן לְפָחוֹת עַד סִיּוּם בִּרְכַּת "הַזָּן":

And all of this is when they bless in zimun according to the ordinance of the Sages, where the mezamen alone blesses and discharges them all of their obligation. But nowadays, when they all bless quietly together with the mezamen — there is no need to be concerned for any of this, and even one who ate only a kazayit and did not drink may bless, even though there are others who ate their fill and drank.
Only that it has already been explained in siman 183 that one should not conduct oneself so, but rather they should listen from the mouth of the mezamen at least until the conclusion of the blessing “hazan.”

מִי שֶׁהָיָה כְּבָר שָׂבֵעַ קֹדֶם שֶׁאָכַל וְאָכַל אֲכִילָה גַּסָּה, אִם נֶהֱנָה גְּרוֹנוֹ מֵאוֹתָהּ הָאֲכִילָה — מְבָרֵךְ לְפָנָיו וּלְאַחֲרָיו, וּמוֹצִיא אֲחֵרִים יְדֵי חוֹבָתָם אַף עַל פִּי שֶׁהֵם חַיָּבִים מִן הַתּוֹרָה וְהוּא אֵינוֹ חַיָּב אֶלָּא מִדִּבְרֵי סוֹפְרִים. אֲבָל אִם נַפְשׁוֹ קָצָה עָלָיו וְאֵין גְּרוֹנוֹ נֶהֱנָה מֵאֲכִילָתוֹ — אֵינוֹ מְבָרֵךְ כְּלָל, לֹא לְפָנֶיהָ וְלֹא לְאַחֲרֶיהָ, לְפִי שֶׁזּוֹ אֵינָהּ חֲשׁוּבָה אֲכִילָה כְּלָל לְכָל מִצְוֹת שֶׁבַּתּוֹרָה, בֵּין לְעִנְיַן מִצְוֹת עֲשֵׂה, כְּמוֹ שֶׁנִּתְבָּאֵר בְּסִימָן תע״ו, בֵּין לְעִנְיַן מִצְוֹת לֹא תַעֲשֶׂה, כְּמָה שֶׁכָּתַבְנוּ בְּסִימָן תרי״ב:

One who was already satiated before he ate and ate an akhilah gassah: if his throat derived enjoyment from that eating — he blesses before and after, and he discharges others of their obligation, even though they are obligated by Torah law while he is obligated only by the words of the Soferim. But if he loathes it and his throat derives no enjoyment from his eating — he does not bless at all, neither before nor after, since this is not considered eating at all for any of the mitzvot of the Torah, whether for positive commandments, as was explained in siman 476, or for negative commandments, as we wrote in siman 612.