Hebrews 7:4-6

4Consider then how great this Melchizedek was. Even Abraham, the great patriarch of Israel, recognized this by giving him a tenth of what he had taken in battle.

5Now the law of Moses required that the priests, who are descendants of Levi, must collect a tithe from the rest of the people of Israel, who are also descendants of Abraham.

6But Melchizedek, who was not a descendant of Levi, collected a tenth from Abraham. And Melchizedek placed a blessing upon Abraham, the one who had already received the promises of God.