It was said unto her,
The elder shall serve the younger.
Read Chapter 9
Augustine of Hippo
AD 430
No one could say that Jacob had conciliated God by meritorious works before he was born, so that God should say this of him…. Nor had Isaac conciliated God by any previous meritorious works, so that his birth should have been promised…. Good works do not produce grace, but are produced by grace. .