Upon examination of the book of Esther, we find that only after we have finished reading the entire book can we retroactively appreciate the significance of all the events it relates. Only after we have seen the picture in its entirety, from the third year of King Achashverosh to the twelfth year of his reign, do the many details join together to form a whole mosaic. Only then do we understand the contribution of each and every detail to the final miracle.
The Megilla reading is preceded by three berakhot: the birkat ha-mitzva (“al mikra megilla”), the birkat ha-nissim (“she-asa nissim”), and the birkat ha-zman (“she-hechiyanu”).
Most of the holidays are mentioned for the first time in the Torah: the holiday of Pesach, the holiday of Matzot, the counting of the Omer, Shavuot, Rosh Hashana, Yom Kippur, Sukkot and Shmini Atzeret. This is not true with respect to Chanuka and Purim.
