Exodus 29:32-34

Aaron and his sons shall eat the meat of the ram and the bread in the basket, at the doorway of the Tent of Meeting. They shall eat those things by which atonement was made at their ordination and consecration; but a layman shall not eat them, because they are holy [that is, set apart to the worship of God]. And if any of the meat of ordination or the bread remains until morning, you shall burn it in the fire; it shall not be eaten, because it is holy.