How are the Old Testament covenants related to the Abrahamic covenant?
The Old Testament covenants are separate covenants, yet all are under the Abrahamic covenant. After God made the Abrahamic covenant, He made the covenant of law, the Davidic covenant concerning the royal family, and the Mosaic covenant concerning the land of Palestine. These distinct covenants operate within and depend on the overarching Abrahamic covenant.
Les explains that the Abrahamic covenant promised a nation of people, a geographical land, and a future time when God would come as their King and Redeemer. After that covenant, God made the covenant of law, the Davidic covenant concerning the royal family, and the Mosaic covenant concerning the land of Palestine. Though these are separate covenants, they are all under the Abrahamic covenant. John the Baptist announced the King who would fulfill that Abrahamic covenant.