God’s promises to his people visibly manifest not only in Isaac, but also in his children, Jacob and Esau. With the preceding example of Isaac and Ishmael, it still concerned two different mothers (Sarah and Hagar). Yet in his second example Paul writes concerning two children originating out of the same womb (Rebekah). He writes: And not only so, but also when Rebekah had conceived children by one man, our forefather Isaac, though they were not yet born and had done nothing either good or bad…she was told, The older will serve the younger
(Romans 9:10–11a, Romans 9:12). The quotation from Genesis 25:23 reminds us of the entire history of the birth of these twins. And in his recollection of that history it again becomes apparent what doctrine Paul wants to emphasize here: in order that God’s purpose of election might continue, not because of works but because of him who calls
(Romans 9:11b). In other words it is not descent, but rather God’s calling (his speaking) that determines our status before him. Jacob therefore owes his privileges not by virtue of being a descendant of Isaac, but to God’s proclamation concerning him.
In later times this passage was often applied to the doctrine of predestination unto eternal life. However, Romans 9:10–12 applies firstly to the places and roles providentially assigned to people in time here on earth. There is a place for Ishmael, but not as a primary figure in God’s history. This also applies to Esau, who also has his unique place in God’s plan, but only in subservience to his younger brother. In both cases, God’s assignment and speaking define people’s specific place and calling. As such when God now calls Gentile Christians to his kingdom during Paul’s time, this is perfectly in line with redemptive history, for it has always been his word that is decisive and this still remains the case. Paul’s point here is that God’s Word is always final.1
10 And not only so, but also when Rebekah had conceived children by one man, our forefather Isaac,