About the festival

Purim, which falls on the 14th of Adar (the 15th in walled cities like Jerusalem), celebrates the deliverance of Persian Jewry 2,400 years ago, during the reign of King Ahasuerus.The story of Purim is recorded in the Book or Scroll  (megillah) of Esther, the only source for this event; the holiday's name, derives from the Hebrew word pur, which refers to the lots cast to determine the day the Jews were to be executed.
Megillah means scroll. There are 5 books in the Bible referred to as  megillot (scrolls): Song of Songs, Ruth, Lamentations, Ecclesiastes, and Esther; each of these is read aloud in the synagogue on a fixed occasion.

Ahasuerus is sometimes identified with Xerxes I, who ruled Persia from 486 to 465 BCE. The first record of the observance of Purim dates from the Hasmonean period (2nd-1st centuries BCE).

In the synagogue

The festival begins with the reading of the  megillah. To mock the memory of Haman, Ahasuerus' evil vizier, listeners stamp on the floor, shout, and use noisemakers made especially for this purpose. The injunction to celebrate Purim with merry-making and drinking is noted already in the Talmudic period, and Purim became the most carnival-like holiday of the Jewish year. Children dress up in costumes, jesters entertain with music.

The story of Megillat Esther tells of King Ahasuerus' wicked chief minister, Haman, who drew lots ( purim in Hebrew) to determine which day the Jews would be exterminated (the date he drew was 13 Adar). Through the intervention of Mordecai and his niece, Queen Esther, the Jewish people were saved. According to the sages, the reading of Megillat Esther on Purim evening and again in the morning, was ordained by Mordecai and Esther themselves.

Noisemakers, called  gragers in Yiddish, and  ra'ashanim in Hebrew, have been a source of much artistic creativity over the centuries.

Community practice

It is customary to read parodies of traditional texts — mock-talmudic tractates, satirical wedding contracts between Haman and his wife, Zeresh, and so on — and to perform special comic plays, known in Eastern Europe as  Purim spielen. In some European Talmudic academies it was customary to elect one of the student as the Purim rabbi, or the rabbi for the day. Many contemporary Jewish schools (particularly in Israel), have an upside down day along this line, with the students teaching the classes (resulting in most cases in bedlam!). In the State of Israel there are also carnival-like parades known as  adlayada.

The textual source for all this topsy-turvy activity is Esther 9:22: "the month which was turned to them from sorrow to joy, and from mourning to holiday..."

adlayada — from the Hebrew word  "ad lo yada" (until he does not know): based on the rabbinic remark that on Purim a man should revel until he does not know to distinguish between "blessed be Mordecai" and "cursed be Haman" (Babylonian Talmud Megillah 7:2).