Exodus 13:10
You shall therefore keep this ordinance in its season from year to year.
Exodus 12:14
And this day shall be unto 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
And you shall observe this thing for an ordinance to you and to your sons forever.
Exodus 23:15
You shall keep the feast of unleavened bread: (you shall eat unleavened bread seven days, as I commanded you, in the time appointed of the month Abib; for in it you 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 unto the LORD: seven days you must eat unleavened bread.
Deuteronomy 16:3-4
You shall eat no leavened bread with it; seven days shall you eat unleavened bread with it, 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.