Exodus 13:10
Thou shall 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 LORD; throughout your generations ye shall keep it a feast by an ordinance forever.
Exodus 12:24-25
And ye shall observe this thing for an ordinance to thee and to thy sons forever.
Exodus 23:15
Thou shall keep the feast of unleavened bread (Seven days thou shall eat unleavened bread, as I commanded thee, at the time appointed in the month Abib, for in it thou came 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 LORD. Ye shall eat unleavened bread seven days.
Deuteronomy 16:3-4
Thou shall eat no leavened bread with it. Seven days thou shall eat unleavened bread with it, even the bread of affliction, for thou came forth out of the land of Egypt in haste, that thou may remember the day when thou came forth