Esausaid,Behold,Iamatthe pointto die: and what profit shall this birthright do to me? And Jacob said, Swear to me this day: and he sware unto him: and he sold his birthright unto Jacob. Then Jacob gave Esau bread and pottage of lentiles; and he did eat and drink, and roseup, and went his way: thus Esau despised his birthright.

-Bible (Old Testament)
Genesis 25:32^4.

They talk about their Pilgrim blood, Their birthright high and holy! A mountain-stream that ends in mud Methinks is melancholy.

-Lowell,James Russell
  'An Interview with Miles Standish', stanza11.

The power of kings and magistrates is nothing else but what is only derivative; transformed and committed to them in trust from the people to the common good of them all, in whom the power yet remains fundamentally, and cannot be taken from them without a violation of their natural birthright.

-Milton,John
^9  The Tenure of Kings and Magistrates.

Boys' hate was dangerous, it was keen and bright, a miraculous birthright, like Arthur's sword snatched out of the stone.

-Munro, Alice ne¤  e Laidlaw
Lives of Girls and Women,'Changes and Ceremonies'.