Genesis 25:29-33

29One day, Jacob was cooking a meal. Esau came back from the country. He was very hungry.

30He said to Jacob ‘Quick, let me have some of that red food! I am very hungry.’ (That is why he was also called Edom.)

31Jacob said, ‘You must first sell me your birthright.’

32Esau said, ‘Look, I am so hungry that I will die. Then my birthright will not help me at all!’

33Jacob said, ‘First, make a serious promise to me.’ So Esau promised to sell his birthright to Jacob.