'Birthright' in the Bible

And Jacob said, Sell me first thy birthright.

And Esau said, Behold, I am about to die. And what profit shall the birthright do to me?

And Jacob said, Swear to me first. And he sware unto him. And he sold his birthright unto Jacob.

And Jacob gave Esau bread and pottage of lentils. And he did eat and drink, and rose up, and went his way. So Esau despised his birthright.

And he said, Is not he rightly name Jacob? for he hath supplanted me these two time. He took away my birthright. And, behold, now he hath taken away my blessing. And he said, Hast thou not reserved a blessing for me?

And they sat before him, the first-born according to his birthright, and the youngest according to his youth: and the men marvelled one with another.