You know that afterwards, when he wanted to receive the blessing that the firstborn son was to receive, he was rejected. Even though he begged and cried for the blessing, he couldn’t do anything to change what had happened.
“The people of Israel will not be able to defend themselves against their enemies. They will run away from their enemies because the people of Israel are now claimed for destruction. I will not be with you anymore unless you destroy what I have claimed for myself.