Leviticus 7:21
Moreover the soul that shall touch any unclean thing, as the uncleanness of man, or any unclean beast, or any abominable unclean thing, and eat of the flesh of the sacrifice of peace offerings, which pertain unto the LORD, even that soul shall be cut off from his people.
Moreover the soul addressed is one who touches any unclean thing — the uncleanness of man, or any unclean beast, or any abominable unclean thing — and then eats of the flesh of the sacrifice of peace offerings which pertain unto the Lord. The surrounding law gives the peace-offerings as an expression of thanksgiving to God.
Those sacrifices pointed forward to the death of Christ and were designed to preserve faith in the coming Redeemer, directing all hearts in gratitude and faith to the great Sacrifice that was to take away the sin of the world. Because of that forward-pointing purpose, the Lord's directions about the offerings had to be strictly obeyed. In the ritual only the fat was to be burned upon the altar, while a certain specified portion was reserved for the priests.
The offering was presented with prayer for God's acceptance and blessing. The greater part was returned to the offerer to be eaten by him and his friends in a sacred sacrificial feast shared from the portion reserved for the people. When properly conducted, the service promoted devotion, piety, kindness, and sympathy rather than empty ceremony or self-gratification. To demand more than the allotted priestly portion, to refuse to wait until the fat had been burned to God, and to seize whatever portion was desired by threat and violence violated this solemn law and turned symbolic service into self-indulgence.