John Calvin Commentary Hebrews 8:7

"For if that first [covenant] had been faultless, then would no place have been sought for a second." — Hebrews 8:7 (ASV)

For if that first, etc. He confirms what he had said about the excellence of the covenant that God has made with us through Christ; and he confirms it on this basis: because the covenant of the Law was neither valid nor permanent. For if nothing was lacking in it, why was another substituted for it? But another has been substituted; and from this it is evident that the old covenant was not perfect in every respect. To prove this, he adduces the testimony of Jeremiah, which we will examine shortly.

But it seems hardly consistent to say that, after having stated that no place would have been sought for the second covenant if the first had been faultless, he should then say that the people were at fault, and that for this reason the new covenant was introduced as a remedy. And thus it appears unjust that if the blame lay with the people, it should be transferred to God’s covenant. Then the argument seems invalid, for even though God might have blamed the people a hundred times, the covenant could not on that account be considered faulty.

The answer to this objection can be easily given. Although the crime of violating the covenant was justly imputed to the people, who had departed from God through their own perfidy, the weakness of the covenant is also pointed out, because it was not written in their hearts. Therefore, to make it perfect and valid, God declares that it needed an amendment. It was not, therefore, without reason that the Apostle contended that a place was to be sought for a second covenant.