Numbers 18:24-26

For the tithes of the children of Israel, which they offer up as a heave offering to the LORD, I have given to the Levites as an inheritance; therefore I have said to them, ‘Among the children of Israel they shall have no inheritance.’ ” Then the LORD spoke to Moses, saying, “Speak thus to the Levites, and say to them: ‘When you take from the children of Israel the tithes which I have given you from them as your inheritance, then you shall offer up a heave offering of it to the LORD, a tenth of the tithe.