Expositor's Bible Commentary 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” introduces the clinching testimony of Scripture, giving the reason for the foregoing. It is quoted verbatim as in 5:6 (see comments) and establishes the special character of Christ’s priesthood, because of no other priest could it be said that his life was “indestructible.” Though it could be said that the Aaronic priesthood was “a priesthood that will continue for all generations” (Exodus 40:15), no individual priest is “forever.”