How long before the giving of the Law were the promises made to Abraham?
The promises given to Abraham were made almost 500 years before the Law was given. The Law does not come in to abrogate or cancel those promises; rather, it enhances them, because if a law could give life, righteousness would have been by the Law.
Les explains that the promises to Abraham were given without the Law, roughly 500 years before the Law was given. He asks whether the Law then cancels the promises, and answers that it does not; instead, it enhances them. The Law was perfect and could have given life if anyone could keep it, but no person can keep the Ten Commandments other than Christ Himself.
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.
Is the law then against the promises of God? God forbid: for if there had been a law given which could have given life, verily righteousness should have been by the law.