Genesis 25:32-34

“Look, I’m dying of starvation!” said Esau. “What good is my birthright to me now?” But Jacob said, “First you must swear that your birthright is mine.” So Esau swore an oath, thereby selling all his rights as the firstborn to his brother, Jacob. Then Jacob gave Esau some bread and lentil stew. Esau ate the meal, then got up and left. He showed contempt for his rights as the firstborn.