The sons of Israel eat unleavened bread because they left Egypt so quickly that the dough didn’t have time to ferment.
Torah, Deuteronomy 16:04: And no leaven shall be seen with you within all your border for seven days; neither shall any of the flesh you slaughter on the preceding day in the afternoon, remain all night until the morning.
Leaven is egoism. “No leaven shall be seen for seven days,” means that no egoism should remain in you.
In order to work correctly with this enormous egoistic desire called Egypt, a person must break away from it fully, and this takes exactly one week (seven days) after which it is possible to start working with it for correction.
Therefore, throughout a year we work with egoism by correcting it, and during the Passover week we don’t use it. It is the same every year, because the renewal happens every time.
Torah, Deuteronomy 16:07: And you shall roast [it] and eat [it] in the place which the Lord, your God, will choose, and you shall turn away in the morning and go to your dwellings.
A person must come to a certain state, certain connection with others, in order to perform the correction of the biggest desires, because meat is the heaviest animalistic desire in him.
After that, we can go back to our usual corrections. This concludes the Pesach (Passover) holiday, and we continue our usual corrections throughout the year.
From KabTV’s “Secrets of the Eternal Book” 8/10/16