John Chrysostom

Thus God made a covenant with Abraham, promising that in his seed the blessing should come upon the heathen; and this blessing the Law cannot turn aside. As this example was not in all respects appropriate to the matter in hand, he introduces it thus, "I speak after the manner of men," that nothing might be deduced from it derogatory to the majesty of God. But let us go to the bottom of this illustration. It was promised Abraham that by his seed the heathen should be blessed; and his seed according to the flesh is Christ; four hundred and thirty years after came the Law; now, if the Law bestows the blessings even life and righteousness, that promise is annulled. And so while no one annuls a man's covenant, the covenant of God after four hundred and thirty years is annulled; for if not that covenant but another instead of it bestows what is promised, then is it set aside, which is most unreasonable.