For the priesthood being changed, there is made of necessity a change also of the law.
For - The reason for pressing the words "after the order of Melchisedek;" because these presuppose a transference of the priesthood; this carries with it a change also of the law (which is inseparably bound up with the priesthood: both stand and fall together, Hebrews 7:11). This is Paul's answer to the objection. What need was there of a new covenant?