Deuteronomy 16:4-6

New Century Version

⁴ 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.

⁵ Do not offer the Passover sacrifice in just any town the Lord your God gives you, ⁶ 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.