Hebrews 7:4-10 NIV

[4] Just think how great he was: Even the patriarch Abraham gave him a tenth of the plunder! [5] Now the law requires the descendants of Levi who become priests to collect a tenth from the people—that is, from their fellow Israelites—even though they also are descended from Abraham. [6] This man, however, did not trace his descent from Levi, yet he collected a tenth from Abraham and blessed him who had the promises. [7] And without doubt the lesser is blessed by the greater. [8] In the one case, the tenth is collected by people who die; but in the other case, by him who is declared to be living. [9] One might even say that Levi, who collects the tenth, paid the tenth through Abraham, [10] because when Melchizedek met Abraham, Levi was still in the body of his ancestor.