Hebrews 7:11

If therefore] RV 'Nowif': the beginning of a new argument. The priesthood is designed to reconcile men to God by removing the barrier between them, viz. sin. Not.. after the order of Aaron] but after the order of Melchizedek, who was independent of Levitical descent, being anterior to it.

13. He of whom these things (i.e. Psalms 110:4) are spoken is Jesus, who belonged to the tribe of Judah, in which the old Law recognises no priests.

15. RV 'And what we say is yet more abundantly evident,' viz. the statement that a change of law is involved in a change of priesthood.

16. Under the old Law priesthood was a matter of physical descent—it was the law of a carnal commandment; but the priesthood of Jesus rests on the power of an indissoluble life (so RV). What constitutes Him priest is not an external commandment, but a power inherent in Him as the eternal Son, who, though as incarnate He died, nevertheless rose from the dead and liveth for ever (Hebrews 7:24). His qualifications were personal, not official.

18, 19. Read,' For there is a disannulling of a preliminary [or, provisional] commandment [viz. that constituting the Levitical priesthood] on account of its weakness and unprofitableness [i.e. its inability to effect atonement for men's sins] (for the law made nothing perfect), and there is the subsequent introduction of a better hope through which we draw near to God.' The words 'for the law made nothing perfect' are a parenthesis. The particular commandment in question was of a piece with the whole Law, which made nothing perfect, i.e. failed in every respect to attain its object, viz. to bring men near to God in reconciliation.