serve the younger
Romans 9:12
9:12 serve the younger. This revelation expressing God’s purpose had been given to Rebekah while the twins were struggling in her womb (Genesis 25:22-23), and she undoubtedly transmitted this word to Isaac, but the latter nevertheless continued to favor Esau over Jacob until God overruled him in traumatic fashion (see notes on Genesis 25–27). It is noteworthy that, in the line of the promised seed, God often chose a younger son, over-riding the natural human tendency to choose the elder (e.g., Seth over Cain, Shem over Japheth, Isaac over Ishmael, Judah over Reuben, Pharez over Er, David over Eliab). Of all in the line of promise whose brothers’ names are given, only Abraham and Jesus Himself were firstborn sons.