18. 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 (Ga 4:7; Ro 8:17; 1Co 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 (Ro 4:14).