Matthew Henry Commentary Galatians 3:15-18

"Brethren, I speak after the manner of men: Though it be but a man`s covenant, yet when it hath been confirmed, no one maketh it void, or addeth thereto. Now to Abraham were the promises spoken, and to his seed. He saith not, And to seeds, as of many; but as of one, And to thy seed, which is Christ. Now this I say: A covenant confirmed beforehand by God, the law, which came four hundred and thirty years after, doth not disannul, so as to make the promise of none effect. For if the inheritance is of the law, it is no more of promise: but God hath granted it to Abraham by promise." — Galatians 3:15-18 (ASV)

The covenant God made with Abraham was not done away by the giving of the law to Moses. The covenant was made with Abraham and his Seed. It is still in force. Christ abides forever in his person, and his spiritual seed, who are his by faith.

By this we learn the difference between the promises of the law and those of the gospel. The promises of the law are made to every person. The promises of the gospel are first made to Christ, then by him to those who are by faith grafted into Christ.

Rightly to divide the word of truth, a great difference must be made between the promise and the law, concerning inward affections and the whole practice of life. When the promise is mingled with the law, it becomes nothing but the law. Let Christ always be before our eyes as a sure argument for the defense of faith against dependence on human righteousness.