Deuteronomy 10:8-9

10:8 At that time the Lord set apart the tribe of Levi to carry the ark of the Lord’s covenant, to stand before the Lord to serve him, and to formulate blessings in his name, as they do to this very day. 10:9 Therefore Levi has no allotment or inheritance among his brothers; the Lord is his inheritance just as the Lord your God told him.