Gen

Gen 25:29-33

One day Jacob was cooking a stew. Esau came in from the field, starved. 30 Esau said to Jacob, "Give me some of that red stew — I'm starved!" That's how he came to be called Edom (Red).

31 Jacob said, "Make me a trade: my stew for your rights as the firstborn."

32 Esau said, "I'm starving! What good is a birthright if I'm dead?"

33 Jacob said, "First, swear to me." And he did it. On oath Esau traded away his rights as the firstborn  

Food that he could see was more important to him than his birthright as the firstborn which he couldn’t see