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.
KJV
Now to Abraham and his seed were the promises made. He saith not, And to seeds, as of many; but as of one, And to thy seed, which is Christ.
ASV
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.
What I mean is this: The law that came 430 years later does not revoke the covenant previously established by God, so as to nullify the promise.
KJV
And this I say, [that] the covenant, that was confirmed before of God in Christ, the law, which was four hundred and thirty years after, cannot disannul, that it should make the promise of none effect.
ASV
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.
Why then was the law given? It was added because of transgressions, until the arrival of the seed to whom the promise referred. It was administered through angels by a mediator.
KJV
Wherefore then [serveth] the law? It was added because of transgressions, till the seed should come to whom the promise was made; [and it was] ordained by angels in the hand of a mediator.
ASV
What then is the law? It was added because of transgressions, till the seed should come to whom the promise hath been made; and it was ordained through angels by the hand of a mediator.