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 for ever.
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.
Now if perfection had been attainable through the Levit'ical priesthood (for under it the people received the law), what further need would there have been for another priest to arise after the order of Melchiz'edek, rather than one named after the order of Aaron? For when there is a change in the priesthood, there is necessarily a change in the law as well. For the one of whom these things are spoken belonged to another tribe, from which no one has ever served at the altar. For it is evident that our Lord was descended from Judah, and in connection with that tribe Moses said nothing about priests.
This becomes even more evident when another priest arises in the likeness of Melchiz'edek, who has become a priest, not according to a legal requirement concerning bodily descent but by the power of an indestructible life. For it is witnessed of him, "Thou art a priest for ever, after the order of Melchiz'edek."