Bible Dictionary
PRIMOGENITURE
Primogeniture is the customary right of the firstborn son to family headship and a double portion of inheritance. Biblical history shows that this privilege could be transferred by divine purpose or parental decision.
Biblical Usage
Biblical history shows birthright and blessing associated with the firstborn, yet also records their transfer from Ishmael to Isaac, Reuben to Joseph, Manasseh to Ephraim, and other younger heirs. Mosaic law protected the firstborn’s double portion from favoritism toward a younger son.