Deuteronomy 16:3-7

You shall not eat leavened bread with it; for seven days you shall eat unleavened bread with it, the bread of affliction (for you came out of the land of Egypt in a hurry), so that you will remember the day when you came out of the land of Egypt all the days of your life.

For seven days no leaven shall be seen with you in your entire territory, and none of the meat which you sacrifice on the evening of the first day shall be left overnight until the morning.

You are not allowed to sacrifice the Passover in any of your towns which the Lord your God is giving you;

but only at the place where the Lord your God chooses to establish His name, you shall sacrifice the Passover in the evening at sunset, at the time that you came out of Egypt.

You shall cook and eat it in the place which the Lord your God chooses. In the morning you are to return to your tents.