Genesis 25:29-33

One day when Jacob was cooking some stew, Esau arrived home from the wilderness exhausted and hungry. Esau said to Jacob, “I’m starved! Give me some of that red stew!” (This is how Esau got his other name, Edom, which means “red.”) “All right,” Jacob replied, “but trade me your rights as the firstborn son.” “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.