Is the law then against the promises of God? - Is it possible that the intervention of the law, in reference to one part of the Abrahamic seed, should annul the promise made to the other? It is impossible.
For if there had been a law, etc. - If any law or rule of life could have been found out that would have given life - saved sinners from death, and made them truly happy, then righteousness- justification, should have been by that law.
Is the law then against the promises of God? - Is the Law of Moses to be regarded as opposed to the promises made to Abraham? Does this follow from any view which can be taken of the subject? The object of the apostle in asking this question is, evidently, to take an opportunity to deny in the most positive manner that there can be any such clashing or contradiction. He shows, therefore, what was the design of the Law, and declares that the object was to further the plan contemplated in the promise made to Abraham. It was an auxiliary to that. It was as good as a law could be; and it was designed to prepare the way for the fulfillment of the promise made to Abraham.
God forbid - It cannot be. It is impossible. I do not hold such an opinion. Such a sentiment by no means follows from what has been advanced; compare the note at Romans 3:4.
For if there had been a law given which could have given life - The Law of Moses is as good as a law can be. It is pure, and truly, and good. It is not the design to insinuate anything against the Law in itself, or to say that as a law it is defective. But law could not give life. It is not its nature; and man cannot be justified by obedience to it. No man has ever yielded perfect compliance with it and no man, therefore, can be justified by it, compare the notes at Galatians 2:16; Galatians 3:10, note.
Verily righteousness should have been by the law - Or justification would have been secured by the Law. The Law of Moses was as well adapted to this as a law could be. No better law could have been originated for this purpose, and if people were to attempt to justify themselves before God by their own works, the Law of Moses would be as favorable for such an undertaking as any law which could be revealed. It is as reasonable, and equal, and pure. Its demands are as just, and its terms as favorable as could be any of the terms of mere law. And such a law has been given in part in order to show that justification by the Law is out of the question. If people could not be justified by a law so pure, and equal, and just; so reasonable in all its requirements and so perfect, how could they expect to be justified by conformity to any inferior or less perfect rule of life? The fact, therefore, that no one can be justified by the pure law revealed on Mount Sinai, forever settles the question about the possibility of being justified by law.