Reuven lost his bechorah (firstborn birthright) to Yosef and kingship to Yehudah because he interfered with Yaakov’s sleeping arrangements after Rachel’s death. While the literal text implies he lay with Yaakov’s concubine Bilhah, the Talmud (Shabbat 55b) states he merely rearranged the beds to defend his mother Leah’s honor.
Reuven, you are my firstborn, my power and the beginning of my strength… Unstable as water, you shall not excel; because you ascended your father’s bed; then you profaned [it]…” – In Bereshit 49:3–4, Yaakov addresses his eldest son directly:
The Biblical Account
The Event: According to Genesis 35:22, Reuven went and lay with Bilhah, his father’s concubine, and Yisrael heard.
The Repercussions: 1 Chronicles 5:1 explicitly states that because Reuven defiled his father’s couch, his birthright was transferred to the sons of Yosef.
Two Main Traditional Perspectives
The Literal View (e.g., Radak, Ramban): Reuven literally committed an act of severe impropriety with Bilhah and was punished by losing the privileges of the firstborn.
The Midrashic/Allegorical View (e.g., Rashi, Shabbat 55b): Reuven did not commit a physical sin. Instead, when Yaakov moved his bed into Bilhah’s tent after Rachel died, Reuven felt it was an insult to Leah. He stepped out of bounds by moving the bed to Leah’s tent. The Torah treats this disrespectful intrusion as gravely as if he had slept with her.
Redistribution of the Firstborn Rights
The loss of the bechorah did not strip Reuven of his lineage, but it divided his privileges among his brothers:
Double Portion: Transferred to Yosef (whose sons Ephraim and Menashe became two separate tribes).
Kehunah (Priesthood): Given to Levi.
Malchut (Kingship): Given to Yehudah.
Key Outcomes for Reuven’s Descendants
Loss of Preeminence: Reuven’s tribe did not ascend to tribal or national leadership. The tribe produced no notable judges, kings, or prophets.
Geographical Settlement: The tribe chose to settle east of the Jordan River (in the lands of Gilead and Jazer) rather than crossing over into the Promised Land of Canaan with the rest of the tribes.
Vulnerability: Because they were geographically separated and easternmost, the tribe of Reuven was among the first to be conquered and exiled by foreign empires (the Assyrians), leading to their status as one of the Ten Lost Tribes of Israel.