A. "And the memory of [Purim] shall never cease - for even though all of the holidays are to be nullified in the future, the days of Purim will not be nullified." (Mid. Mish 9:1 on Est. 9:28).
Let us now explain this.
A parable. Two people were given a task to serve as night watchmen, and to try and recognize all of the people who approached. The first person lit a candle, and held it up towards everyone, and peered into their faces using the light. The second person did not light a candle - so how, then, did they try to recognize others? They worked on strengthening their sense of hearing.
Now, the first person was ultimately better at the task of discerning those who approached, as their power of sight was clearer and more distinct than the one who could only utilize their power of hearing. On the other hand, the actions of the second person were advantageous in a different way, in that they trained themselves and strengthened their skill of listening to the voices of others. The first person did not do this.
Behold, then, that in the morning, when the dawn breaks, and the first person blows out their candle - for "what use is a candle in the middle of the day?" - any advantage they had gained from the use of the candle at night is now extraneous. But the second person, who can certainly see clearly during the daytime, also retains the powers of listening and hearing that they developed during the night: these powers have been eternally acquired in this person's soul.
B. Behold, in a Jewish leap year (shana m'uberet), the Megilla is read during Adar II. The reason is that we juxtapose the salvation of Purim to the salvation of Egypt.
We must understand the following: the salvation of Egypt has a statement of "I am God" (Anochi - Ex. 20:2): I am the Lord Your God who took you out of Egypt." So too, the salvation of Purim has its own "I am God" (Deut 31:18): "I, God, will keep my Face hidden." This is related to the Talmud's question - "where in the Torah do we find an allusion to Esther? Anochi hasteir asteer (I [God] will hide my Face). This is to say, the Jewish people have two ways of recognizing the Anochi/God: through the salvation of Egypt, and through the salvation of Purim.
Discerning God through the salvation of Egypt is like the person who recognizes others with the help of a light; but discerning God through the salvation of Purim is like the person who uses other senses of their own.
And we can continue to follow this line of thinking. When dawn ultimately breaks, and the sun shines brightly, the "light of the sun shall become seven-fold" (Is. 30:26) - the perception of God's light shall become seven-fold the light of the sun. Because of this, the "lights" that the Jewish people had previously needed will no longer be necessary, and will automatically be nullified.
And therefore, all of the holidays which are remembrances of the Exodus from Egypt: when the future day will come, that a future salvation will become primary and past salvations will be subsidiary, all of these holidays will become absorbed within the light of the future salvation. However, all of this is only true regarding the other holidays, whose core event is the Exodus. But Purim, during which the Jews taught themselves to discern the Anochi from within darkness and hiding - certainly this power/strength will remain in the soul of the Jewish people even after the future dawn will break. All the holidays will be nullified, except for Purim, as the verse states: "its memory will never cease."
C. It seems, then, that there are two types of light. The first is, "God is my light", in general. The second is "Though I sit in darkness, God is my light" (Micah 7:8). The unique illumination of Purim is in discerning the light that sparks even within the depths of darkness. And just as the power which guides a person's steps in the darkness is also beneficial in the light, so too those aspects of insight/penetration which shine from within the un-knowingness of "Until one doesn't know the difference" are of untold value.
Pachad Yitzchak
