According to tradition, the birthright usually passed from father to eldest son. The first mention in the Old Testament of a younger brother receiving the blessing is that of Rebekah arranging Isaac to confer the blessing upon Jacob rather than Esau.
In The Way to Perfection, Elder Joseph Fielding Smith wrote: "We may not know all the circumstances concerning the call of Jacob over Esau, and just why the Lord chose the younger to inherit the rights of priesthood and appointed the older to serve the younger. We may say in truth, that Jacob was more faithful and gave better heed to the commandments of the Lord. This would entitle him to the blessings, for let it be remembered that all blessings are predicated on faithfulness, and this according to a law `irrevocably decreed in heaven before the foundations of the world, . . . and when we obtain any blessing from God, it is by obedience to that law upon which it is predicated.'"On this ground, then, Jacob was entitled to supplant Esau, if there was any such thing as a supplanting. Our history of those events informs us that Jacob was called before he was born to inherit these blessings. Then they were given him by the highest Authority, and who dare question the right of that Authority to bestow the blessings?"
In Mormon Doctrine, Elder Bruce R. McConkie wrote: "Lineage alone does not guarantee the receipt of whatever birthright privileges may be involved in particular cases. Worthiness, ability, and other requisites are also involved. Jacob prevailed over his older brother Esau because `Esau despised his birthright.' (Gen. 25:24-34; 27; Rom. 9:10-12.) The Lord placed Ephraim (the younger) before Manasseh to fulfil His own purposes (Gen. 48); and Nephi, . . . was made a ruler and a teacher over [his older brothersT, a circumstance that became the cause of much contention for many generations."
