Wrong choices in marriage are long to be repented of and bring a great length of sorrow. But the situation could not be remedied in the way that Esau thought. His action only added problems to the situation for God had commanded that one man should take one wife, and now he was breaking this commandment again. He ought instead to have accepted that he had done evil and repented of it. He should have seen that there was no point in trying to regain the first place in his father’s favour, since that had gone to Jacob by the will of God and could not be recovered. His past sin had led to this situation and he must now accept the consequences and not strive against them. He ought, as Calvin says, to have humbled himself under the hand of God and tried to find blessing through the covenant renewed with his brother, accepting that although he was the elder he had been given the second place.
The unbeliever and the believer are worlds apart. The unbeliever always underestimates what it is to know God and to please him. He thinks that faith can be reduced to some outward actions without any change of the heart, without true conversion. Jacob was almost certainly not converted until later when he came to Bethel, but Esau was right to see him as the one favoured by God, and now by his father also. He thinks he can earn that blessing for himself, or at least put himself back in his father’s favour by taking a non-Canaanite wife. He has given some serious thought to this. But no one can make themselves a child of God by attempting to live as a believer would live. If the heart remains unregenerate, then all that comes out of it will be unacceptable to God, no matter how closely it resembles the good works of the believer. The motive is wrong, and the goal is wrong.