'Birthright' in the Bible

and Jacob saith, 'Sell to-day thy birthright to me.'

And Esau saith, 'Lo, I am going to die, and what is this to me -- birthright?'

and Jacob saith, 'Swear to me to-day:' and he sweareth to him, and selleth his birthright to Jacob;

and Jacob hath given to Esau bread and pottage of lentiles, and he eateth, and drinketh, and riseth, and goeth; and Esau despiseth the birthright.

And he saith, 'Is it because one called his name Jacob that he doth take me by the heel these two times? my birthright he hath taken; and lo, now, he hath taken my blessing;' he saith also, 'Hast thou not kept back a blessing for me?'

And they sit before him, the first-born according to his birthright, and the young one according to his youth, and the men wonder one at another;