The battles fought between the Jews and their enemies, which took place on Adar 13 throughout the Persian empire (see "Today in Jewish History" for that date), continued for two days -- Adar 13 and 14 -- in the capital city of Shushan, where there were a greater number of Jew haters. Thus the victory celebrations in Shushan were held on the 15th of Adar, and the observance of the festival of Purim was instituted for that day in Shushan and all walled cities. (See Laws and Customs below).
On this date, in the year following the Holy Temple’s destruction, G‑d tells Ezekiel to take up a lamentation for Pharaoh, king of Egypt, and for the Jewish nation’s other enemies, foretelling their ultimate downfall.
Read the prophecy here: Ezekiel ch. 32
In cities that are surrounded by a wall dating from the days of Joshua (13th century BCE) -- a prominent example is the city of Jerusalem -- the festival of Purim is observed on the 15th of Adar (instead of the 14th), in commemoration of the fact that in the ancient walled city of Shushan, the first Purim was celebrated on this day (see "Today in Jewish History").
All over the world, Tachanun is omitted due to the special joy of the day.
(For an overview of the Purim observances and links to more information, see "Laws and Customs" for Adar 14.)
“And now, if You will forgive their sin, and if not, obliterate me from Your book that you have written.” (Exodus 32:32)
Moses’ plea can be read two ways. The simple reading is to add a single word: “If you will forgive their sin, good, and if not..”
But you can also read it as it is written:
Whether you forgive them or not, obliterate me.
Why? Why would Moses demand not only his physical death, but utter, eternal, spiritual obliteration? Moses, of all people, who certainly was fully cognizant of what this meant!
Certainly it was out of his love for his people. Because G‑d had told him, “Let me destroy them and I will make you into a great nation.”
At this, Moses shuddered with his entire being.
If not for him, G‑d could not destroy the Jewish people. After all, G‑d had promised their forefathers that their descendants would become a great nation.
If so, it was his existence that made possible the destruction of his own people.
Repulsed and horrified, Moses exclaimed, “Such a creature I cannot be! Please! Obliterate me as though I never was!”
This is a Jewish leader. There is no cell in his body that is not made of love for his people.