And this I say, that the covenant, that was confirmed before by God in Christ, the law, which was four hundred and thirty years after, cannot disannul, that it should make the promise of no effect.
All Commentaries on Galatians 3:17 Go To Galatians 3
Augustine of Hippo
AD 430
If the law justifies, Abraham was not justified, since he lived long before the law. Since they cannot say this, they are forced to admit that a man is justified not by works of the law but by faith. And he compels us to understand that all the ancients who were justified were justified from the same faith. For as we are saved by believing partly in a past event, that is, the first coming of the Lord, and partly in a future one, that is, his second coming, they believed the whole of it, that is, both comings as events. The Holy Spirit reveals this for their salvation.