Galatians 3:17-19
3:17 What I am saying is this: The law that came four hundred thirty years later does not cancel a covenant previously ratified by God, so as to invalidate the promise.
3:18 For if the inheritance is based on the law, it is no longer based on the promise, but God graciously gave it to Abraham through the promise.
3:19 Why then was the law given? It was added because of transgressions, until the arrival of the descendant to whom the promise had been made. It was administered through angels by an intermediary.