The Relationship Between Jacob and Esau

Esau's response to Jacob let us know that he himself is not without sin. He looks like Cain, Lamech and we've pointed to ways that he looks like Ishmael. So this murderous response to the disappointment that his father's pleasure does not actually come to him,. His father's blessing does not come to him. And so I think that the text is identifying Esau as seed of the serpent for us.