Exodus 12:42
It is a night to be much observed unto the LORD for bringing them out from the land of Egypt: this night should be observed unto the LORD by all the sons of Israel in their ages.
Deuteronomy 16:1-6
Keep the month of the new fruit, and thou shalt do the passover unto the LORD thy God; for in the month of the new fruit the LORD thy God brought thee forth out of Egypt by night.
Exodus 12:14
And this day shall be unto you for a memorial; and ye shall keep it as a feast unto the LORD throughout your ages; ye shall keep it a feast by an ordinance forever.
Exodus 13:10
Thou shalt, therefore, keep this ordinance in its season from year to year.