Numbers 18:24-27

²⁴For 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.

²⁵And the Lord said to Moses,

²⁶Say to the Levites, When you take from the children of Israel the tenth which I have given to you from them as your heritage, a tenth part of that tenth is to be offered as an offering lifted up before the Lord.

²⁷And this lifted offering is to be put to your credit as if it was grain from the grain-floor and wine from the vines.