The promises were spoken to Abraham and to his seed. The Scripture does not say, “and to seeds,” meaning many, but “and to your seed,” meaning One, who is Christ.
16. Now to Abraham, and his seed. Before pursuing his argument, he introduces an observation about the substance of the covenant, that it rests on Christ alone. But if Christ be the foundation of the bargain, it follows that it is of free grace; and this too is the meaning of the word promise.
Abraham was justified by faith, and so are all believers. Scripture foresaw that God would justify the heathen through faith in Christ; therefore believers of any nation, blessed as Abraham was, are justified in the same way he was.
AI summary
Commenting on Galatians 3:6-18
Now to Abraham and his seed were the promises made,.... The promises design the promises of the covenant of grace mentioned in the next verse, which are exceeding great and precious, better than those of any other covenant; and which are all yea and amen in Christ, and are chiefly of a spiritual nature; though all the temporal blessings of God's people come to them...