The Megillah tells us that Haman cast lots to determine the date of the annihilation of the Jewish people (Source 1). The Talmud tells us that Haman was happy that it fell on Adar, thinking that — it being the month Moses died — it was a bad omen for the Jewish people. He didn’t realize that it was also the month of his birthday (Source 2).
The Rebbe cites these sources and asks: What is actually more significant? Which day overrides which? Is the negative omen of death stronger than the positive omen of birth?
B. Birthday or Yahrzeit?
The Rebbe elaborates the question: When contrasting a birthday with a day of death, the birthday seems insignificant. When a child is born, we know nothing at all about his future. In contrast, at death we know everything the person accomplished. In that case, the inherent negativity in Adar, due to the loss of such a great personage like Moses, should surely outweigh the seemingly positive aspect of his birth.
The answer is the Moses is unique. From the moment of his birth, the home was filled with his radiance (source 3). The contribution of Moses was evident from the outset, and therefore, his birthday outweighs the day of his passing.
As the Rebbe explains in Source 4 & 5, the radiance of Moses represented the light of the Torah, and that is something that continues to live on through the generations. Haman didn’t understand that the spiritual life of Moses — which continues until today — was far more significant than the loss of his physical body.
C. The Moses in You
Every Jew has a spark of Moses; every Jew has a pintele yid that treasures Judaism, Torah and its commandments. The lesson of 7 Adar is: awaken your passion and reveal your inner radiance. Be a Moses!