It is a common understanding amongst people that contracts need to be honoured once they have been made. Unless there is a new agreement involving both original parties, the conditions are fixed and binding.1 If this is true of human agreements (Genesis 21:22–32; Genesis 26:26–31; Genesis 31:44–45; 1 Samuel 18:3; 1 Samuel 20:8; 1 Samuel 22:8; 1 Samuel 23:18; 2 Samuel 3:12), how much more for a covenant made by God?2 Paul mentions this reality because he seeks to argue from the lesser (human covenants) to the greater (a covenant given by God). He wants to make it clear that a covenant made by God with Abraham cannot be revoked or changed by a later covenant.3 The promise to Abraham, coming before the law thus serves to support justification by faith.4
15 To give a human example, brothers: even with a man-made covenant, no one annuls it or adds to it once it has been ratified.