Genesis 25:26

25:26 And after that came his brother out, and his hand took hold on Esau’s heel; and his name was called Jacob: and Isaac [was] threescore years old when she bare them.

Genesis 25:33-34

25:33 And Jacob said, Swear to me this day; and he sware unto him: and he sold his birthright unto Jacob. 25:34 Then Jacob gave Esau bread and pottage of lentiles; and he did eat and drink, and rose up, and went his way: thus Esau despised [his] birthright.