Jacob compares Reuben to water in a strong current to emphasize that he cannot control his anger and he is not stable. (See: [[rc://en/ta/man/jit/figs-simile]])
Here "bed" and "couch" stand for Jacob's concubine, Bilhah. Jacob is referring to when Reuben slept with Bilhah ([Genesis 35:22](../35/22.md)). Alternate translation: "because you went to my bed and slept with Bilhah my concubine. You have shamed me" (See: [[rc://en/ta/man/jit/figs-metonymy]])