Deuteronomy 16:3-5

Modern English Version

³ You must not eat leavened bread with it. For seven days you must eat unleavened bread, the bread of affliction, for you came out of the land of Egypt in a hurry, so that you may remember all the days of your life the day when you came out of the land of Egypt. ⁴ There must not be any leavened bread seen with you within all your borders for seven days, nor may any of the meat which you sacrificed in the evening on the first day remain overnight until morning.

⁵ You may not sacrifice the Passover within any of your gates that the Lord your God has given you.