# If one forgot Al HaNissim in Benching, one doesn’t repeat benching. However, if one remembers that he forgot Al HaNissim while still benching one should add it in the Harachaman’s by saying Harachaman Hu Yaaseh Lanu Nissim and continue with Al HaNissim. <Ref>Mishna Brurah 695:15 </ref>
==Drinking on Purim==
# The mitzvah to drink only applies to wine.
Most authorities, Ashkenazic and Sephardic, hold that one should only drink a little more than what one is accustomed to drink and then sleep (see note for procedure). <Ref> Bet Yosef 695:1 quotes the Orchot Chaim who writes that it’s forbidden to get drunk; rather the mitzvah is to drink a little more than one is accustomed to drink. Darkei Moshe HaAruch 695:2 quotes the Mahariv as saying that one should drink, and then sleep so that one doesn’t know the difference between Arur Haman and Baruch Mordechai. Rama 695:2 combines the Orchot Chaim and Mahariv saying that one should drink more than one is accustomed to drink and then sleep.
* Mishna Brurah 695:5 explicitly rules that this is the accepted halacha. This was also the minhag of Rav Shlomo Zalman (Halichot Shlomo pg 343 note 78). Rav Schachter (“Inyanei Purim”, min 91-3) explained that one should drink a little more than one is accustomed to, and then fall asleep after the meal. Rabbi Willig (min 42-6), however, explained that according to the Rama one should drink a little, sleep, and then have the Seudah, and drink a little in the meal. Yalkut Yosef 695:14 rules like the Orchot Chaim and makes no mention of sleeping. Rav Mordechai Eliyahu in MaAmer Mordechai 64:36 who seems to agree.
* Rashi Megillah 7b D”H LeIvsumei and Rambam 2:15 specify wine and not other intoxicating drinks. Kaf HaChaim 695:6 and Nitai Gavriel 73:2 codify this as halacha. Rabbi Willig (min 44-5) rules that it’s prohibited to have intoxicating drinks other than wine on Purim or any day of the year. However, Shalmei Todah (pg 326) quotes Rav Nissim Karlitz saying that it’s not MeAkev to have wine specifically. Rav Shlomo Zalman (Halichot Shlomo pg 342, note 76) writes that grape juice does not suffice. </ref> All agree that if one going to end up violating or degrading any halacha such as Birkat HaMazon, one should not get drunk. <Ref> The Chaye Adam 155:30 writes that if one knows that getting drunk will cause one to degrade fulfilling a mitzvah such as making Brachot, Birkat HaMazon, or Maariv, one shouldn’t get drunk. This is quoted by the Biur Halacha D”H Ad and Kaf HaChaim 695:17. This is supported by the Mieri (Megillah 7b) who writes that we’re not commanded to have happiness of vanity and frivolity, rather one should have happiness that leads to Ahavat Hashem and a desire to thank Him for the miracles he did for us. </ref>