Read Genesis 25:33 Using Other Translations
And Jacob said, Swear to me this day; and he sware unto him: and he sold his birthright unto Jacob.
Jacob said, "Swear to me now." So he swore to him and sold his birthright to Jacob.
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.