Exodus 12:14

12:14 This day will become a memorial for you, and you will celebrate it as a festival to the Lord – you will celebrate it perpetually as a lasting ordinance.

Exodus 12:24

12:24 You must observe this event as an ordinance for you and for your children forever.

Exodus 23:15

23:15 You are to observe the Feast of Unleavened Bread; seven days you must eat bread made without yeast, as I commanded you, at the appointed time of the month of Abib, for at that time you came out of Egypt. No one may appear before me empty-handed.

Leviticus 23:6

23:6 Then on the fifteenth day of the same month will be the festival of unleavened bread to the Lord; seven days you must eat unleavened bread.

Deuteronomy 16:3-4

16:3 You must not eat any yeast with it; for seven days you must eat bread made without yeast, symbolic of affliction, for you came out of Egypt hurriedly. You must do this so you will remember for the rest of your life the day you came out of the land of Egypt. 16:4 There must not be a scrap of yeast within your land for seven days, nor can any of the meat you sacrifice on the evening of the first day remain until the next morning.