In the Old Testament, the eldest son of Jacob and Leah (Gen. 29: 32; 37: 21-22, 29; 42: 22, 37). Although Reuben was the firstborn, he lost his birthright because of sin (Gen. 35: 22; 49: 3-4).

The tribe of Reuben: Jacob’s blessing to Reuben is found in Genesis 49: 3 and Deuteronomy 33: 6. The tribe’s numbers gradually diminished, and though the tribe continued to exist, it became politically less important. Reuben’s birthright went to Joseph and his sons because Joseph was the firstborn son of Jacob’s second wife, Rachel (1 Chr. 5: 1-2).