One of the lesser-known duties of the Purim holiday is the obligation to sleep. This obligation is mentioned explicitly in the Rema: “A person should drink more than he his accustomed to, so that he may sleep” (OC 695:2).
The source for this obligation is the statement of Rava, that a person is obligated “livsumei beforaya” – which we can translate “to perfume himself [with the scent of wine] in bed” (Megillah 7b). In this way his drinking is most likely to lead to the object of sleep.
We can find a basis for this obligation in the fact that the entire Purim miracle was a result of sleep. For example, Haman convinces Achashverosh to make his evil decree against the Jews by telling him, “Yeshno am echad”(3:8) – “There is a nation” which doesn’t abide by the customs of the kingdom. The gemara tells us that Haman used this term to imply, “Yashnu am echad” – a people slept (from the commandments) (Megillah 13b).
Based on this model, we can discover a similar hint in the treatment of Esther. We learn that Esther had an advantage over the other maidens brought to Achashverosh because the caretaker of the women liked her especially, and gave her serving girls, “veyishaneha” – he treated her differently; but we can also read, “veyashna” – she slept. It seems that because her needs were taken care of by servants, she was able to obtain her beauty sleep which gave her favor in the eyes of the king.
When Esther realizes the gravity of the situation, she calls all the Jews to gather and make a three-day period of fasting and prayer. What is the significance of specifically three days? The gemara tells us that this is the period in which a person can definitely not go without sleep (Nedarim 15a). It seems that an essential part of this period of repentance was that it should include sleep.
We also know that the beginning of the miracle began with sleep, for it began as the king was reminded of Mordechai’s unrequited service, when he had his books read for him because he could not sleep (6:1).
The Shulchan Arukh specifically has to tell us that one who nodded off during the megilla reading has not fulfilled his obligation (OC 690:12). This requirement is not mentioned regarding the Torah reading, but because of the special importance of sleep during Purim, it was necessary to explicate it with reference to the Megillah.
We can see that those who stay up all night on Purim preparing elaborate mishlochei manot are not fulfilling their Purim obligations in the ideal way. Rather, each of us should be sure to sleep at least a bit on this holiday.
Pleasant Purim dreams!