Numbers 18
23 Ref But the Levites are to do the work of the Tent of meeting, and be responsible for errors in connection with it: this is a law for ever through all your generations; and among the children of Israel they will have no heritage.
24 Ref For the tenths which the children of Israel give as a lifted offering to the Lord I have given to the Levites as their heritage. and so I have said to them, Among the children of Israel they will have no heritage.