Deuteronomy 16:3-8

Do not eat it with bread made with yeast. But for seven days eat bread made without yeast, the bread of suffering, because you left Egypt in a hurry. So all your life you will remember the time you left Egypt. There must be no yeast anywhere in your land for seven days. Offer the sacrifice on the evening of the first day, and eat all the meat before morning; do not leave it overnight. Do not offer the Passover sacrifice in just any town the LORD your God gives you, but offer it in the place he will choose to be worshiped. Offer it in the evening as the sun goes down, which is when you left Egypt. Roast the meat and eat it at the place the LORD your God will choose. The next morning go back to your tents. Eat bread made without yeast for six days. On the seventh day have a special meeting for the LORD your God, and do not work that day.