Exodus 13:10
You shall therefore keep this ordinance in its season from year to year.
Exodus 12:14
This day shall be to you for a memorial, and you shall keep it a feast to the LORD: throughout your generations you shall keep it a feast by an ordinance forever.
Exodus 12:24-25
You shall observe this thing for an ordinance to you and to your sons forever.
Exodus 23:15
You shall observe the feast of unleavened bread. Seven days you shall eat unleavened bread, as I commanded you, at the time appointed in the month Abib (for in it you came out from Egypt), and no one shall appear before me empty.
Leviticus 23:6
On the fifteenth day of the same month is the feast of unleavened bread to the LORD. Seven days you shall eat unleavened bread.
Deuteronomy 16:3-4
You shall eat no leavened bread with it. You shall eat unleavened bread with it seven days, even the bread of affliction; for you came forth out of the land of Egypt in haste: that you may remember the day when you came forth out of the land of Egypt all the days of your life.