Charles Ellicott Commentary Leviticus 22:2

"Speak unto Aaron and to his sons, that they separate themselves from the holy things of the children of Israel, which they hallow unto me, and that they profane not my holy name: I am Jehovah." — Leviticus 22:2 (ASV)

Separate themselves from the holy things of the children of Israel. — As parts of the sacrifices offered by the Israelites belonged to the priests, they are here warned that they are not to consider themselves absolutely entitled to them under all circumstances, and that there are times when they must abstain from them.

In those things which they hallow unto me. — That is, in their treatment of the sacrifices which the children of Israel have consecrated and offered to the Lord.