John Wesley on Romans 9:10

And that God's blessing does not belong to all the descendants of Abraham, appears not only by this instance, but by that of Esau and Jacob, who was chosen to inherit the blessing, before either of them had done good or evil. The apostle mentions this to show, that neither were their ancestors accepted through any merit of their own. That the purpose of God according to election might stand - Whose purpose was, to elect or choose the promised seed. Not of works - Not for any preceding merit in him he chose. But of him that called - Of his own good pleasure who called to that privilege whom he saw good.