Leviticus 19:3-7

Every one of you shall revere his mother and his father, and you shall keep My Sabbaths; I am the Lord your God.

Do not turn to idols or make for yourselves cast metal gods; I am the Lord your God.

‘Now when you offer a sacrifice of peace offerings to the Lord, you shall offer it so that you may be accepted.

It shall be eaten on the same day you offer it, and on the next day; but what remains until the third day shall be burned with fire.

So if it is eaten at all on the third day, it is unclean; it will not be accepted.