Galatians 3:18 - Matthew Poole's English Annotations on the Holy Bible

If the inheritance of the heavenly Canaan, typified by the earthly Canaan, the promise of which was made to Abraham, be to be obtained by the fulfilling of the law, and yielding obedience to it, then it is no more of the promise. It is much the same with what the apostle said before, Romans 4:14; and with what he had said, Romans 11:6: If by grace, then it is no more of works, otherwise grace is no more grace. But if it be of works, then it is no more grace; otherwise work is no more work. He shows, that there is an opposition between grace and work, the law and the promise; that which is of grace, and of the promise, is of free love; that which is of works, and the law, is wages, and a reward of debt. But (saith the apostle) God gave the inheritance to Abraham by promise; he of his free love engaging himself thereunto.