Numbers 18:24-26

24because I have given them the Israelites’ tithes, which have been presented as sacred offerings to the Lord. This will be the Levites’ share. That is why I said they would receive no allotment of land among the Israelites.”

25The Lord also told Moses,

26“Give these instructions to the Levites: When you receive from the people of Israel the tithes I have assigned as your allotment, give a tenth of the tithes you receive—a tithe of the tithe—to the Lord as a sacred offering.