Galatians 3:16

3:16 Now the promises were spoken to Abraham and to his descendant. Scripture does not say, “and to the descendants,” referring to many, but “and to your descendant,” referring to one, who is Christ.

Galatians 3:19-20

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. 3:20 Now an intermediary is not for one party alone, but God is one.