The right that naturally belonged to the father’s firstborn son. Both the Hebrew and Greek terms for “birthright” (bekho·rahʹ; pro·to·toʹki·a) come from roots having the basic idea of “firstborn.”

Under the patriarchal system, upon the death of the father the oldest son became the head of the family, with authority over the others as long as they were in the household. He was responsible to care for the members of his father’s household. He also succeeded to the father’s position in representing the family before Jehovah. The firstborn generally received the father’s special blessing. (Ge 27:4, 36; 48:9, 17, 18) Moreover, he was entitled to two parts of the father’s estate; that is, he received twice as much as each of his brothers. Under the Mosaic Law a man with more than one wife could not take the birthright from the oldest son and give it to the son of a specially loved wife.​—De 21:15-17.

In patriarchal times the birthright could be transferred by the father to another son for a cause, as in the case of Reuben, who lost his right as firstborn because of fornication with his father’s concubine. (1Ch 5:1, 2) The firstborn could sell his birthright to one of his brothers, as did Esau, who despised his birthright and sold it to his brother Jacob in exchange for one meal. (Ge 25:30-34; 27:36; Heb 12:16) There is no record that Jacob asserted his purchased birthright in order to get a double share of Isaac’s property (which was movable or personal property, for Isaac owned no land, except the field of Machpelah, in which was a cave for a burial place). Jacob was interested in passing on spiritual things to his family, that is, the promise given to Abraham concerning the seed.​—Ge 28:3, 4, 12-15.

With respect to the kings of Israel, the birthright seems to have carried with it the right of succession to the throne. (2Ch 21:1-3) However, Jehovah, as Israel’s real King and their God, set aside such right when it suited his purposes, as in the case of Solomon.​—1Ch 28:5.

Jesus Christ, as “the firstborn of all creation,” always faithful to his Father Jehovah God, has the birthright through which he has been appointed “heir of all things.”​—Col 1:15; Heb 1:2; see INHERITANCE.