Numbers 18:19-21

¹⁹All the firstfruits of the sanctuary which the children of Israel offer to the Lord, I have given to thee and to thy sons and daughters, by a perpetual ordinance. It is a covenant of salt for ever before the Lord, to thee and to thy sons.

²⁰And the Lord said to Aaron: You shall possess nothing in their land, neither shall you have a portion among them: I am thy portion and inheritance in the midst of the children of Israel.

²¹And I have given to the sons of Levi all the tithes of Israel for a possession for the ministry wherewith they serve me in the tabernacle of the covenant: