But the Lord clearly indicated that there should be an exception to the rule in this case and that Jacob should be the heir and not Esau.

When it was known that the mother would bear two sons, and just before the time of their birth, Rebekah the mother inquired of the Lord concerning the expected children and the Lord said unto her that two sons would be born to her and that the elder should serve the younger.

(Genesis 25:22,23) This definitely shows that it was God's purpose that Jacob, who was born last, should be the heir and successor to the Abrahamic promise.
[108]These two sons grew to manhood's estate.

Esau became a great hunter and loved the outdoor sports; while Jacob was a plain man, remaining quietly at home.

Esau showed that he did not appreciate the birthright, viz., the Abrahamic promise, even if it were his, which in fact it was not, since God had foreordained that it should belong to Jacob.