Hebrews 7:4-6

New Catholic Bible

⁴ Just consider now how great this man must have been for the patriarch Abraham to give him a tenth of his spoils. ⁵ The descendants of Levi who succeed to the priestly office are required by the Law to collect tithes from the people, that is, from their fellow countrymen, although they too are descended from Abraham. ⁶ However, Melchizedek, who was not of the same ancestry, received tithes from Abraham and blessed him who had received the promises.