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 regular years, the 15th of Adar is Shushan Purim, the festival that celebrates -- in Jerusalem and other ancient walled cities -- the salvation of the Jewish people from Haman's evil decree in the year 3405 from creation (356 BCE). In a leap year -- which has two Adars -- Shushan Purim is observed in Adar II, and the 15th of Adar I is designated as Shushan Purim Kattan, the "Minor Shushan Purim."
There are no special observances associated with Shushan Purim Kattan, other than the omission of Tachnun ("supplications") from the daily prayers and a prohibition against fasting or holding eulogies on this day. The Code of Jewish Law cites an opinion that one should increase in festivity and joy, but rules that there is no obligation to do so; "Nevertheless,a person should increase somewhat in festivity... for 'One who is of good heart is festive always' " (Shulchan Aruch, Orach Chaim 697:1).
The last written work of the Rebbe before his stroke centered on the following thought. The Rebbe personally handed a copy to thousands of people. I believe it is a summary of who we are and what we must do:
Self-sacrifice in a land of freedom penetrates to the bone.
I saw men and women who sacrificed all they had to defy the religious persecution of the Bolshevik regime. They came to a land of freedom and comfort—where is their greatness now?
Then there is the child of that land of freedom and comfort, worshipping it, chasing after it—but inside he is crushed by the spiritual void. His inner being does not let him alone, the spark inside that cries, “This is not what I truly want! I don’t want this world! I don’t want any worlds! All I want is Him alone!”
This is the crushing of an olive for its oil. The oil spreads and penetrates every fiber of his being. His every faculty begins to burn. And there shines the source of light that can never be extinguished nor dimmed.
It is the light from which the messianic era is formed.