Hebrews 6:17-7:10

So when God desired to show more convincingly to the heirs of the promise the unchangeable character of his purpose, he interposed with an oath, so that through two unchangeable things, in which it is impossible that God should prove false, we who have fled for refuge might have strong encouragement to seize the hope set before us. We have this as a sure and steadfast anchor of the soul, a hope that enters into the inner shrine behind the curtain, where Jesus has gone as a forerunner on our behalf, having become a high priest forever after the order of Melchiz'edek. For this Melchiz'edek, king of Salem, priest of the Most High God, met Abraham returning from the slaughter of the kings and blessed him; and to him Abraham apportioned a tenth part of everything. He is first, by translation of his name, king of righteousness, and then he is also king of Salem, that is, king of peace. He is without father or mother or genealogy, and has neither beginning of days nor end of life, but resembling the Son of God he continues a priest forever. See how great he is! Abraham the patriarch gave him a tithe of the spoils. And those descendants of Levi who receive the priestly office have a commandment in the law to take tithes from the people, that is, from their brethren, though these also are descended from Abraham. But this man who has not their genealogy received tithes from Abraham and blessed him who had the promises. It is beyond dispute that the inferior is blessed by the superior. Here tithes are received by mortal men; there, by one of whom it is testified that he lives. One might even say that Levi himself, who receives tithes, paid tithes through Abraham, for he was still in the loins of his ancestor when Melchiz'edek met him.