Reuben: Commits Incest with One of his Father's Concubines, And, in Consequence, Forfeits his Birthright
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Genesis 35:22
While Israel was living in that region, Reuben went in and slept with his father’s concubine Bilhah, and Israel heard about it. Jacob had twelve sons:
Genesis 49:4
Uncontrolled as the waters, you will no longer excel, because you went up to your father’s bed, onto my couch, and defiled it.
1 Chronicles 5:1
These were the sons of Reuben the firstborn of Israel. Though he was the firstborn, his birthright was given to the sons of Joseph son of Israel, because Reuben defiled his father’s bed. So he is not reckoned according to birthright.