Deuteronomy 16:5

³Thou shalt not eat leaven with it; seven days shalt thou eat unleavened bread with it, bread of affliction, because ye came forth out of Egypt in haste; that ye may remember the day of your coming forth out of the land of Egypt all the days of your life.

⁴Leaven shall not be seen with thee in all thy borders for seven days, and there shall not be left of the flesh which thou shalt sacrifice at even on the first day until the morning.

— Deuteronomy 16:5 —

⁶But in the place which the Lord thy God shall choose, to have his name called there, thou shalt sacrifice the Passover at even at the setting of the sun, at the time when thou camest out of Egypt.

⁷And thou shalt boil and roast and eat it in the place, which the Lord thy God shall choose; and thou shalt return in the morning, and go to thy house.