- It is a Mitzvah to eat a lavish and festive meal on Purim. This Mitzvah is a Biblical command, as rejoicing on Purim is from the words of Scripture which has the same power as the words of Torah. One fulfills his obligation through eating even a single meal on Purim day.
- When? It is an obligation to eat one festive meal on Purim during daytime. One does not fulfill his obligation with a meal eaten the previous night, and certainly not with a meal eaten on Motzei Purim. Customarily, it is eaten after an early Mincha. One is to beware to eat the majority of the meal while it is still day.
- Learning prior to meal: Prior to commencing the meal, one should learn words of Torah, as this protects him from any damage occurring to him during the meal. [It is proper to learn Mishnayos from Tractate Shekalim before the meal, and Tractate Megila after the meal.]
- The menu: It is a Mitzvah to have delicacies and festive foods eaten during this meal. It is best to wash on bread for this meal. It is a proper custom to bake bread on Erev Purim so one have fresh bread available, just like is the custom on Erev Shabbos. It is disputed whether it is an obligation for one to eat [animal] meat during the Purim meal however according to all it is a Mitzvah to do so. One is to eat grains and legumes, in commemoration of the Zaronim which Daniel ate in Bavel. It is customary to eat a triangular shaped pastry filling called Haman-Tashen. One is to gather his family and friends for the Purim Seuda as it is not possible to rejoice alone.
- Getting drunk: Men are obligated to get drunk [on wine] on Purim to the point they cannot differ between “blessed is Mordechai and cursed is Haman”. Some rule there is no need to drink alcohol to this point, and it rather suffices to drink slightly more than the norm and then sleep. Whichever opinion one decides to follow, whether he drinks more or drinks less, his intentions are to be for the sake of heaven. In some Sichos the Rebbe applied the decree to Purim as well. In other Sichos the Rebbe said the decree does not apply to Purim. After a thorough analysis of each source it seems the Rebbe’s opinion leans to apply the decree to Purim as well. [Practically each person is to seek advice with his Asei Lecha Rav, and whichever one does he should do so for the sake of heaven.]
- The Mitzvah of drinking wine is to be fulfilled during the day, by the Purim meal. Seemingly one is to reach this state prior to sunset, as is the time frame of fulfillment for all of the Mitzvos on Purim. One fulfills his obligation with any form of alcohol. Nevertheless it is best to get drunk on wine, as the main miracles of Purim took place through wine.
- Birchas Hamazon: In the grace after meals one adds Al Hanissim. If the meal extended into the night one is to nevertheless recite Al Hanisim in his Bentching. If one Davened Maariv prior to Bentching he no longer says Al Hanissim in Bentching. [Thus one is to avoid Davening Maariv prior to Bentching in order so he be able to Al Hanissim.] If one forgot to say Al Hanissim and has finished Bentching he has nevertheless fulfilled his obligation and does not need to repeat Birchas Hamazon. If he remembered before reciting Hashem’s name in the blessing of “Al Haaretz Veal Hamazon” then he is to go back to Al Hanissim. If however one has already recited Hashem’s name, then if one has not yet concluded Birchas Hamazon, he is to recite “Harachaman Hu Yaaseh Lanu Nissim Viniflaos Kemo Sheasa Laavoseinu Bayamim Haheim Bezman…Bimeiy Mordechai”, in the orders of Harachmans which are recited.
- May one Daven Maariv or Bentch if he is drunk? One may say all blessings even if he is very drunk to the point he cannot speak before a king. Initially one is to recite Birchas Hamazon prior to becoming drunk to the point one cannot speak before a King. If one did not do so, then [if he became satiated from the meal] he is to bentch even in a very drunk state. It is only forbidden to Daven under the influence of alcohol if: One drank to the point he cannot walk straight or feels extremely under the influence. If one consumed more than a Revius and feels slightly tipsy then he must Daven within a Siddur.