Charles Ellicott Commentary Numbers 18:24

"For the tithe of the children of Israel, which they offer as a heave-offering unto Jehovah, 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." — Numbers 18:24 (ASV)

But the tithes ... — Better, for the tithes ... This verse assigns the reason why the Levites were to have no inheritance among the children of Israel.