Numbers 18:20-27

²⁰And the LORD said unto Aaron: 'Thou shalt have no inheritance in their land, neither shalt thou have any portion among them; I am thy portion and thine inheritance among the children of Israel.

²¹And unto the children of Levi, behold, I have given all the tithe in Israel for an inheritance, in return for their service which they serve, even the service of the tent of meeting.

²²And henceforth the children of Israel shall not come nigh the tent of meeting, lest they bear sin, and die.

²³But the Levites alone shall do the service of the tent of meeting, and they shall bear their iniquity; it shall be a statute for ever throughout your generations, and among the children of Israel they shall have no inheritance.

²⁴For the tithe of the children of Israel, which they set apart as a gift unto the LORD, I have given to the Levites for an inheritance; therefore I have said unto them: Among the children of Israel they shall have no inheritance.'

²⁵And the LORD spoke unto Moses, saying:

²⁶'Moreover thou shalt speak unto the Levites, and say unto them: When ye take of the children of Israel the tithe which I have given you from them for your inheritance, then ye shall set apart of it a gift for the LORD, even a tithe of the tithe.

²⁷And the gift which ye set apart shall be reckoned unto you, as though it were the corn of the threshing-floor, and as the fulness of the wine-press.