Romans 9:10

And not only. Paul now gives a still clearer illustration of the same principle. It might be objected that the election of Isaac and the rejection of Ishmael are easily understood on the basis that Sarah was Abraham’s wife, whereas Hagar was but a bondwoman (Gen. 16:1). But the choice of Jacob over Esau could not be explained this way, for their origins were identical.

But when Rebecca also. The sentence beginning with these words is interrupted by the parenthesis in verse 11 and then continued in verse 12. The meaning, however, is clear. Rebecca is mentioned, rather than Isaac, since it was to her that the prophecy quoted in verse 12 was addressed.

By one. These words emphasize that there was only one father. Yet, though Jacob and Esau had the same father and the same mother, the peculiar stations appointed them in life were different.

Our father Isaac. The twins had for their father the patriarch of the chosen race. However, Jacob was the one chosen to be the progenitor of the nation through which God planned to spread abroad a knowledge of His will.