Numbers 18:19-21

¹⁹all the heave-offerings of the holy things which the sons of Israel lift up to Jehovah I have given to thee and to thy sons, and to thy daughters with thee, by a statute age-during, a covenant of salt, age-during it is before Jehovah, to thee and to thy seed with thee.'

²⁰And Jehovah saith unto Aaron, 'In their land thou dost not inherit, and a portion thou hast not in their midst: I am thy portion, and thine inheritance in the midst of the sons of Israel;

²¹and to the sons of Levi, lo, I have given all the tenth in Israel for inheritance in exchange for their service which they are serving — the service of the tent of meeting.