Exodus 13:10
You shall therefore keep this law in its season from year to year.
Exodus 12:14
And this day shall be a memorial to you. And you shall keep it as a feast to Jehovah throughout your generations. You shall keep it as a feast by a law forever.
Exodus 12:24-25
And you shall observe this thing for a law 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 of Egypt. And no one shall appear before Me empty.
Leviticus 23:6
and on the fifteenth day of the same month is the Feast of Unleavened Bread to Jehovah. You must eat unleavened bread seven days.
Deuteronomy 16:3-4
You shall eat no leavened bread with it. Seven days you shall eat unleavened bread with it, the bread of affliction, for you came forth out of the land of Egypt in haste, so that you may remember the day that you came forth out of the land of Egypt all the days of your life.