Our sages said that the story of the exodus from Egypt should be said in a manner of question and answer. One who does not have anyone to ask him asks himself “What has changed,” etc.
We should interpret this. “Story” comes from the words, “the heavens tell.” The exodus from Egypt means the liberation and redemption from the Klipot [shells/peels] and the Sitra Achra [other side], meaning to invoke the root of redemption and extend it. This matter is regarded as “the heavens tell,” meaning that when one removes oneself from any worldliness, he can tell the praise of the Creator.
Yet, in order for one to rise to heaven, his work is in a manner of question and answer. This is the meaning of the sons asking, since Banim [sons] means Havanah [understanding] and reason and intellect, and they ask him.
One who has no sons—whose mind and reason have no questions because he is pure in his reason and qualities—must evoke the questions by himself, as Baal HaSulam interpreted the words of our sages, “I awaken the dawn, and the dawn does not awaken me.”
“What has changed this night compared to all other nights?”
“Night” means the body, which is regarded as “deficiency” and “darkness.” “Day” means the soul, which illuminates the body. At that time, he asks, “How has his body changed from the rest of the bodies of the nations of the world?” “For on all other nights,” the bodies eat what they want without any scrutinies. Rather, whatever their hearts desire, they say is in their favor. But this night, my body is limited in both thought and desire.
The explanation is, “We were slaves… and He delivered us.” That is, specifically through these limitations we will be able to emerge from exile. Precisely by seeing the changes and ascents and descents each time, by struggling, a place of prayer awakens. Then the words “And the children of Israel sighed from the work, and their cry went up” come true. If the exile is revealed in full, then begins the redemption.
This shows us the order of exile and redemption that took place in Egypt at that time, and this is the order we must extend through the end of correction.