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").
(For an overview of the Purim observances and links to more information, see "Laws and Customs" for Adar 14.)
Joseph had two sons in Egypt. From their names, we learn how a human being can be successful in this world.
He named the first son Menasheh, which means to forget. Whenever Joseph called Menasheh, he remembered that this land was causing him to forget his true home and all that his father had taught him.
And so he never forgot.
He named his second son Ephraim, which means to be productive. Whenever Joseph called Ephraim, he remembered that he had a purpose to accomplish in Egypt, so that his family could eventually settle there in dignity and prosperity.
And so he was successful.
Just as the names of both sons were crucial to Joseph’s success, so too every human being must keep two memories awake at all times:
This material world is not your true place, for your soul descended into this body from a luminous, heavenly place.
And you are here for a purpose, to channel that heavenly light into this world.
Menasheh came first, but Ephraim, Jacob later told Joseph, was greater.
Because first you must remember that this is not your true place.
And only then will you remember to accomplish your true purpose, to bring this earthly world in harmony with that place from which you came.