Deuteronomy 16:1-4

“In honor of the LORD your God, celebrate the Passover each year in the early spring, in the month of Abib, for that was the month in which the LORD your God brought you out of Egypt by night. Your Passover sacrifice may be from either the flock or the herd, and it must be sacrificed to the LORD your God at the designated place of worship—the place he chooses for his name to be honored. Eat it with bread made without yeast. For seven days the bread you eat must be made without yeast, as when you escaped from Egypt in such a hurry. Eat this bread—the bread of suffering—so that as long as you live you will remember the day you departed from Egypt. Let no yeast be found in any house throughout your land for those seven days. And when you sacrifice the Passover lamb on the evening of the first day, do not let any of the meat remain until the next morning.