A thought from R. Gershon Henich of Radzin (Sod Yesharim). Just as before the giving of the Torah there needed to be a great slumber, so too at the time of the Purim story Israel was sleeping as the verse states “ישנו עם אחד.”
When a person is sleeping all that they have is their most reflexive trait and the most natural trait of a Jew that is revealed in a state of complete darkness, unconsciousness and sleep in their love for HaShem.
It is specifically when you peel away all the other – even holy – distractions that this essence is revealed.
(Sod Yesharim, Pg. 31)