Brothers, I'm using a human illustration. No one sets aside even a human covenant that has been ratified, or makes additions to it.
References for Galatians 3:15
Now the promises were spoken to Abraham and to his seed. He does not say "and to seeds," as though referring to many, but and to your seed, referring to one, who is Christ.
References for Galatians 3:16
And I say this: the law, which came 430 years later, does not revoke a covenant that was previously ratified by God, so as to cancel the promise.
References for Galatians 3:17
For if the inheritance is from the law, it is no longer from the promise; but God granted it to Abraham through the promise.