For if that first covenant had been without fault, no place would have been sought for a second.
7. For if that first, etc. He confirms what he had said of the excellency of the covenant which God has made with us through Christ; and he confirms it on this ground, because the covenant of the Law was neither valid nor permanent; for if nothing was wanting in it, why was another substituted for it?
In this part of the chapter, the apostle illustrates and confirms the superior excellency of the priesthood of Christ above that of Aaron, from the excellency of that covenant, or that dispensation of the covenant of grace, of which Christ was the Mediator (Heb 8:6): his ministry is more excellent, by how much he is the Mediator of a better covenant.
Commenting on Hebrews 8:6-13
For if that first covenant had been faultless,.... Not the covenant of works; that was made in paradise, this on Mount Sinai; that was made with Adam and his posterity, this with the Jews only; that had no mediator, this had one, Moses; that was not dedicated with blood, this was; that had no forgiveness of sin in it, this had; under that saints are...