Siman 682

All eight days of Chanukah, one says "Al HaNissim" in Birkat HaMazon in the blessing of the land. And that is: he begins "Nodeh Lecha" and says until "u-ve-chol sha'ah," and afterwards says "Ve-al HaNissim" until "le-shimcha ha-gadol." And afterwards he says "Ve-al ha-kol Hashem Elokeinu anachnu modim lach..." And similarly in the prayer after "Modim" until "kivinu lach": "Ve-al HaNissim" until its end, and afterwards he says "Ve-al kulam... ve-chol ha-chayim yoducha selah..." Because these blessings are not a prayer but rather an expression of thanks, and "Al HaNissim" is also an expression of thanks, and therefore they established it in the expression of thanks. This is not the case with "Ya'aleh Ve-Yavo" – it is a prayer, and they established it in the blessing of prayer in "Retzei." And it appears to me that one must say "Ve-al HaNissim" since there are also expressions of thanks beforehand, and this is an addition. And in the prayer books it is written "Al HaNissim," but it seems that one must say it with a Vav.

One must say "keshe-amdah... ha-rish'ah" – the resh with a sheva, and the shin and ayin with a kamatz. And one must say "le-hashkicham Toratecha, u-le-ha'aviram chukei retzonecha" without mems (Magen Avraham). And some say "me-chukei" (Pri Chadash), and so we say, for this phrasing is simpler. And we say "keshe-amdah... al amcha Yisrael," and there is no need to say "keshe-amdah aleihem," for this is a redundancy of language, since we say "al amcha Yisrael." And one must say at its conclusion "ve-kave'u shemonat yemei Chanukah elu," and not like those who say "shemonah yamim elu" and do not mention Chanukah, for it is not so, as every matter must be mentioned explicitly (ibid.). And we say "ve-al ha-teshu'ot ve-al ha-milchamot." And some say "ve-al ha-nifla'ot." And it appears to me that on Chanukah one should say "ve-al ha-milchamot" since the Hasmoneans fought against Antiochus. But on Purim there was no war, and one should say "ve-al ha-nifla'ot." And we say "keshem she-asita la-avoteinu...", and our teacher, the Beit Yosef, wrote that we do not say "keshem she-asita..." but rather he concludes "ve-asita imahem nissim u-gevurot ba-yamim ha-hem..." And some say that we do say it. Thus far his words. And the reason for the first opinion: that "keshem" implies the language of prayer, that just as You did for our ancestors – so may You do for us, and we do not say prayer in the final three [blessings of the Amidah]. But some say that we do say it, and such is our custom. For a congregation is different, just as we say during the Ten Days of Repentance "u-chetov...", "u-ve-sefer chayim."

If one forgot "Al HaNissim," whether in the prayer or in Birkat HaMazon – we do not make him return. For it is not similar to "Ya'aleh V'Yavo" of Rosh Chodesh and Chol HaMoed, which are days that have a Musaf sacrifice. This is not the case with Chanukah, which is merely an expression of thanksgiving. However, if he remembered within that same blessing – as long as he did not say the Name, even if he said "Blessed are You" and remembered – he returns. And even though he is not obligated to return, nevertheless, in Birkat HaMazon he should say in the "HaRachaman" at their end: "May the Merciful One perform for us miracles and wonders, just as You performed... in the days of Matityahu" until its end. And so too in the prayer, he can say "Al HaNissim" after "Yihyu L'Ratzon" (Taz). And know that on Shabbat one must say "Al HaNissim" also in Musaf, and likewise in the Musaf of Rosh Chodesh Tevet. And even though there is no Musaf on Chanukah – nevertheless, it is a day that became obligated in four prayers, and one must mention that of Chanukah in all of them.