Numbers 18:24-26

Instead, I give to the Levites as their inheritance the tithes that the Israelites present as an offering to the LORD. That is why I said concerning them: ‘They will have no inheritance among the Israelites.’ ” The LORD said to Moses, “Speak to the Levites and say to them: ‘When you receive from the Israelites the tithe I give you as your inheritance, you must present a tenth of that tithe as the LORD’s offering.