Is the law then contrary to the promises of God? Certainly not! For if a law had been given that could give life, then righteousness would indeed be by the law.
21. Is the law then against the promises of God? The certainty and steadiness of the divine purpose being admitted, we are bound equally to conclude that its results are not contrary to each other. Still there was a difficulty to be resolved, arising from the apparent contradiction between the Law and the covenant of grace. This is, perhaps, an exclamation.
The law was given to convince men of sin and to restrain them from running into excess. It was never meant to overthrow the promise, but to serve it by directing sinners to Christ, the only way sin is expiated and pardoned.
AI summary
Commenting on Galatians 3:19-29
Is the law then against the promises of God?.... If the law was added because of transgressions, and curses for them, and if the inheritance is not of it, but by promise, were it, it would not be by promise, then, says an objector, it is against the promises: these are contrary to one another, and God, in giving the one and the other, must...