Exodus 13:10
Thou shalt therefore keep this ordinance in its season from year to year.
Exodus 12:14
And this day shall be to you for a memorial; and ye shall keep it a feast to the LORD throughout your generations: ye shall keep it a feast by an ordinance for ever.
Exodus 12:24-25
And ye shall observe this thing for an ordinance to thee and to thy sons for ever.
Exodus 23:15
Thou shalt keep the feast of unleavened bread: (thou shalt eat unleavened bread seven days, as I commanded thee, in the time appointed of the month Abib; for in it thou camest out from Egypt: and none shall appear before me empty:)
Leviticus 23:6
And on the fifteenth day of the same month is the feast of unleavened bread to the LORD, seven days ye must eat unleavened bread.
Deuteronomy 16:3-4
Thou shalt eat no leavened bread with it; seven days shalt thou eat unleavened bread with it, even the bread of affliction; for thou camest forth from the land of Egypt in haste: that thou mayest remember the day when thou camest forth from the land of Egypt, all the days of thy life.