The phrases "my firstborn, my might" and "the beginning of my strength" mean the same thing. The words "might" and "strength" stand for Jacob's ability to produce children. The words "firstborn" and "beginning" mean that Reuben is his first child. AT: "my first child after I became a man" (See: [[rc://en/ta/man/translate/figs-parallelism]])
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/translate/figs-simile]])
Here "bed" and "couch" stand for Jacob's concubine, Bilhah. Jacob is referring to when Reuben slept with Bilhah (See: [Genesis 35:22](../35/21.md)). AT: "because you went to my bed and slept with Bilhah my concubine. You have shamed me" (See: [[rc://en/ta/man/translate/figs-metonymy]])
# you went up to your father's bed ... you went up to my couch
Both statements mean the same thing. (See: [[rc://en/ta/man/translate/figs-parallelism]])