The Four Mitzvot (Commandments) of Purim

(20) Mordecai recorded these events. And he sent dispatches to all the Jews throughout the provinces of King Ahasuerus, near and far, (21) charging them to observe the fourteenth and fifteenth days of Adar, every year— (22) the same days on which the Jews enjoyed relief from their foes and the same month which had been transformed for them from one of grief and mourning to one of festive joy. They were to observe them as days of feasting and merrymaking, and as an occasion for sending gifts to one another and presents to the poor. (23) The Jews accordingly assumed as an obligation that which they had begun to practice and which Mordecai prescribed for them... (28) Consequently, these days are recalled and observed in every generation: by every family, every province, and every city. And these days of Purim shall never cease among the Jews, and the memory of them shall never perish among their descendants... (31) These days of Purim shall be observed at their proper time, as Mordecai the Jew—and now Queen Esther—has obligated them to do, and just as they have assumed for themselves and their descendants the obligation of the fasts with their lamentations. (32) And Esther’s ordinance validating these observances of Purim was recorded in a scroll.

One is obligated to read the entire Megillah. And the obligation is to read it once in the night and once during the day. It is permissible to read the night time reading at any time during the night and to read the daytime reading at any time during the day.

If one read the Megillah by heart, they have not fulfilled their duty. If a speaker of a foreign tongue heard the Megillah read from a copy written in the Hebrew language and in Hebrew script, they have fulfilled their duty, even though they did not know what they said. Similarly, if the Megillah is written in Greek, and they heard it read, they have discharged their duty, even though they know no Greek, and even if the listener is familiar with Hebrew.

What is the nature of our obligation for this feast? A person should eat meat and prepare as attractive a feast as his means permit.

Rava said: A person is obligated to become intoxicated with wine on Purim until he is so intoxicated that he does not know how to distinguish between cursed is Haman and blessed is Mordecai.

Some say it is not necessary to become drunk so much, but rather to drink more than he is used to (Kol Bo), and to fall asleep, and while he sleeps he does not know [the difference] between "accursed is Haman" and "blessed is Mordechai" (Maharil).

And similarly a a person is obligated to send two portions of meat or two types of cooked food or two types of food to his friend, as it says (Esther 9:22) "and send portions one man to another" two portions to one man. And all that increase to send to others is praiseworthy.

The Gemara relates that Abaye bar Avin and Rabbi Ḥanina bar Avin would exchange their meals with each other to fulfill their obligation of sending portions on Purim.

The mishna mentions: And gifts distributed to the poor. Rav Yosef taught a baraita that the verse states: “And of sending portions one to another” (Esther 9:22), indicating two portions to one person. The verse continues: “And gifts to the poor” (Esther 9:22), indicating two gifts to two people.