“Adar marks the fall and defeat of Haman, the descendant of Amalek….

Nothing has the ability to weaken one’s enthusiasm and joy in serving God as much as the denial of God’s hashgacha (providence). If one’s fate is left to chance, then the entire world seems cold and foreign, and there is no reason to serve God…Amalek cooled the fire of enthusiasm that burned in Bnei Yisrael, and injected despair and despondency into their hearts…[and] came to negate the happiness and the eagerness in the Jews’ service of God.

…

In the month of Adar – the eve of Nisan, when the Almighty’s miraculous Providence was revealed – another stage was added in the destruction of the seed of Amalek. The obliteration of ‘Amalekism’ was advanced through a hidden miracle (which is in fact superior in its essence to a revealed one…), through Divine intervention in the history of Bnei Yisrael.

Through this hidden intervention, ‘The Jews had light, and happiness, and joy, and honor’ (Esther 8:16).”