Galatians 3:18

“For if the inheritance be of the law, etc..] By the inheritance is meant, either the eternal inheritance, everlasting life and happiness in heaven, which is the gift of God through Christ, and not attained to and enforced by the works of the law; or particularly the blessing of justification, promised in the covenant to Abraham, and his spiritual seed; even to the Gentiles, and inherited by them; which is not obtained through obedience to the law of works, nor does it belong to those who seek for it by the deeds of the law, for these are not heirs of it; (see <450414>Romans 4:14). For was this the case, it is no more of promise; it cannot be by merit and by promise, by works and grace too;…”

“the inheritance--all the blessings to be inherited by Abraham's literal and spiritual children, according to the promise made to him and to his Seed, Christ, justification and glorification (Gal 4:7; Rom 8:17; Co1 6:9). but God, &c.--The Greek order requires rather, "But to Abraham it was by promise that God hath given it." The conclusion is, Therefore the inheritance is not of, or from the law (Rom 4:14).”

“For if the inheritance - The inheritance promised to Abraham. The sum of the promise was, that “he should be the heir of the world;” see Romans 4:13, and the note at that verse. To that heirship or inheritance Paul refers here, and says that it was an essential part of it that it was to be in virtue of the promise made to him, and not by fulfilling the Law. Be of the law - If it is by observing the Law of Moses; or if it come in any way by the fulfilling of law. This is plain. Yet the Jews contended that the blessings of justification and salvation were to be in virtue of the observance of the Law of Moses. But if so, says Paul, then it could not be by the promise made to Abraham, since…”

“And again - This is a new argument. The former was drawn from the time, this from the nature, of the transaction. If the eternal inheritance be obtained by keeping the law, it is no more by virtue of the free promise - These being just opposite to each other. But it is by promise. Therefore it is not by the law. Galatians 3:19”

“3:18 The inheritance (see 4:1-7) cannot come through keeping the law, because that would nullify God’s promise to Abraham, which was accepted by faith before the law.”

“if: Gal 3:10, Gal 3:12, Gal 3:26, Gal 3:29, Gal 2:21; Rom 4:13-16, Rom 8:17 but: Gal 3:16; Psa 105:6-12, Psa 105:42; Mic 7:18-20; Luk 1:54, Luk 1:55, Luk 1:72, Luk 1:73; Heb 6:12-15 Galatians 3:19”