Charles Ellicott Commentary Hebrews 7:17

"for it is witnessed [of him,] Thou art a priest for ever After the order of Melchizedek." — Hebrews 7:17 (ASV)

For he testifieth.—A slight change of reading makes the sense clearer: For witness is borne to him—as to this power of indissoluble life—in the words of the prophecy itself.