It is reasonable to ask: Both in Tanakh and in rabbinic literature (Bamidbar Rabba ch. 10, Vayikra Rabba 12:1), it is made clear that drunkenness is disgraceful and liable to bring one to sin. Why, then, are we commanded to get drunk on Purim? The reason is that all the miracles that God performed for the Jewish people on Purim happened through wine. Vashti was removed from her reign at the wine feast, and Esther then took her place. Haman’s demise occurred at a wine feast as well. We must therefore conclude that although drunkenness is generally disgraceful, one cannot ignore its positive aspects. Through wine, simple joy is made manifest and unconstrained material happiness, filled with strength and vitality, is expressed. Throughout the year, the disrepute and rowdiness that associated with drunkenness overshadow its positive aspects, and thus drunkenness causes many problems. On Purim, however, when we drink and rejoice over God’s salvation, in commemoration of the miracles He performed through drinking – the positive aspects of drinking are expressed.
There is a deeper reason as well. On Purim, the eternal sanctity of Israel is revealed, and it becomes clear that everything God does to the Jewish people is for the good. Even things that initially seem bad eventually turn out to be for our benefit. Drinking wine for the sake of a mitzva shows that even the material aspect of Israel is holy at its core. Even though the body and its senses seem to impede the service of God, this is reversed on the sublime plane of Purim, when these physical elements greatly enhance our service of God, with joy and vitality.
Let us delve even deeper. In general, Torah and intellect must guide our lives, and when one follows this path, he is happy, but his happiness is limited by his perception. However, on the lofty level of faith that we reach on Purim, we recognize that God runs the world for the good. Even if His ways are sometimes incomprehensible to us, we disregard our own perceptions and happily accept God’s governing of the world. This is the level of "until he does not know": cleaving to God Who is beyond human comprehension. This is connected in its entirety to faith through self-sacrifice. With such sublime faith – the faith of the people of Israel – we achieve boundless joy. 15

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