What laws governed the inheritance of birthright in the Old Testament?

Daniel H. Ludlow, director of teacher support, Church Educational System Several customs and traditions of the Hebrews are related to this question, namely, patriarchal government, primogeniture, and polygyny.

The patriarchs in the Old Testament times usually governed their families directly—their wives, sons, unmarried daughters, families of the sons, and so on. When the father died, he was succeeded as head of the family by a son.

So that there would be no disputation as to which son would succeed the father, the practice of primogeniture, or the law of the firstborn, developed. (Prime means “first”; geniture has to do with birth.) Upon the death of the father, the firstborn (eldest) son became the new head of the family. As this was his right because of the order of his birth, he was referred to as the birthright son (see Gen. 43:33). The birthright son was entitled to a double portion (that is, twice as much as any other son) of the father’s inheritance—one portion as a son, the second portion as the new head responsible for the family (see Gen. 48:22; Deut. 21:17), including the care of his mother and unmarried sisters. As firstborn son, under the Aaronic order, he also held the right of presiding over the family. (See also the “Bible Dictionary” in the new LDS edition of the King James Bible, pp. 625, 675.)

When the father had only one wife, there was no question as to who the birthright son would be. However, in those days the Lord permitted some of his patriarchs to have more than one wife (polygyny). Thus the father might have several “firstborn” sons, possibly one from each of his wives. The question then naturally arose as to which firstborn son of which wife would become the head of the entire family upon the death of the father. Custom and tradition indicated that the first wife should have precedence over the other wives; thus it was determined that the firstborn son of the first wife would be the birthright son as long as he proved worthy. Only in case of unworthiness or death would the birthright go to the firstborn son of the second wife. No second-born sons were considered for the birthright unless all firstborn sons proved to be unworthy.

An understanding of these customs helps one to understand the following episodes in the Bible concerning the “right to rule” among the patriarchs.

Isaac and Ishmael

The Bible lists three wives for Abraham: Sarah, Hagar, and Keturah. Hagar, the second wife, was the first to have a son, Ishmael. Ishmael was thus the birthright son of Abraham as long as the first wife (Sarah) did not have a son. When Sarah gave birth to Isaac, Isaac held the birthright because he was the firstborn son of the first wife.

Jacob and Esau

The Bible lists Rebekah as the only wife for Isaac, and from that marriage came twin sons: Esau, the firstborn, and Jacob. As the firstborn son of the first wife, Esau was the birthright son according to the practice of primogeniture. However, Esau proved to be unworthy of the birthright because he did not marry within the covenant group as desired by his father and mother (see Gen. 26:34–35). Also, Esau, at least temporarily, lost his desire for the birthright and sold it to Jacob for some “bread and pottage of lentils” (see Gen. 25:29–34; Heb. 12:16). Jacob, the second-born son, then became the birthright son of Isaac. Even before the twins were born, the Lord informed Rebekah: “Two nations are in thy womb … and the one people shall be stronger than the other people; and the elder shall serve the younger” (Gen. 25:23). This fact should be kept in mind to understand why Rebekah wanted her husband, Isaac, to give the greater blessing to Jacob.

Joseph and Reuben

Jacob, also known as Israel, married at least four wives in the following order: Leah, Rachel, Bilhah, and Zilpah. From these wives Jacob had twelve sons (listed in the order of their birth, with the name of the mother in parentheses): (1) Reuben (Leah), (2) Simeon (Leah), (3) Levi (Leah), (4) Judah (Leah), (5) Dan (Bilhah), (6) Naphtali (Bilhah), (7) Gad (Zilpah), (8) Asher (Zilpah), (9) Issachar (Leah), (10) Zebulun (Leah), (11) Joseph (Rachel), and (12) Benjamin (Rachel).

As the firstborn son of the first wife, Reuben was the birthright son. When Reuben proved to be unworthy by committing adultery with Bilhah (see Gen. 35:21–22; Gen. 49:3–4), the birthright went to the firstborn son of the second wife—Joseph, the son of Rachel (see 1 Chr. 5:1). Although Joseph was the eleventh-born son in order of birth, he was second in line for the birthright because he was the firstborn son of the second wife. Jacob had a special coat made for Joseph so that the other brothers would recognize Joseph’s right to preside over the family upon his father’s death.

Ephraim and Manasseh

As far as the Bible indicates, Joseph had only one wife, Asenath, and they had only two sons: Manasseh, the firstborn, and Ephraim (see Gen. 41:50–52). When Joseph brought his two sons to their grandfather Jacob for a father’s (or patriarchal) blessing, it is obvious that Joseph expected Manasseh to receive the greater blessing, and it “displeased” Joseph when Jacob “set Ephraim before Manasseh” and gave the greater blessing to the younger brother (Gen. 48:17–20). Neither the Bible nor modern scripture explains specifically why Jacob departed from the usual practice of primogeniture, but the Joseph Smith Translation (JST, Gen. 48:5–11) and the Doctrine and Covenants (D&C 133:32–34) indicate that Jacob was directed by the Lord in giving the greater blessing to Ephraim. Thus Ephraim received the birthright of Joseph, and Joseph received the birthright of Jacob (Israel). In a sense, then, Ephraim is the birthright son of Israel, as confirmed by the Lord through his prophet Jeremiah: “I am a father to Israel, and Ephraim is my firstborn” (Jer. 31:9).