“While Israel dwelt in that land, Reuben went and laid with Bilhah his father’s concubine. Israel heard of it.”
This is a strange notation. Rueben, the oldest son of Leah, slept with his father’s concubine, Bilhah. Bilhah was Rachel’s maid. Her two children were Dan and Naphtali so that Reuben and Dan and Naphtali had the same father but different mothers. So Reuben has sex with his step mother. Now Israel heard about it, but there is nothing to indicate that he did anything about it.