EXO 12:17

17 and ye shall keep (the feast of) therf bread. For in that same day I shall lead out of the land of Egypt your host; and ye shall keep this day in your generations by everlasting custom. (and ye shall keep the Feast of Unleavened Bread. For on that day I led your host out of the land of Egypt; and ye shall remember this day in all your generations to come, by an everlasting rite.)