“Reuben, you are my firstborn, my might and the beginning of my power,
Pre-eminent in dignity, and pre-eminent in strength,
Uncontrolled as water you will not be pre-eminent,
Because you went up to your father's bed,
Then you defiled it. You went up to my couch.”
Jacob first describes Reuben in terms of being his firstborn. As such he had been his father's strength and the beginning of Jacob's power base as found in his sons.
But Reuben has little future for he has revealed his weakness in his sexual behaviour. Such weakness has destroyed many men and Reuben is no exception. Because of it he is a nonentity. He was a dignified man with a certain strength of character, but he was also not of leadership material, lacking the necessary ability to control and direct. And he had revealed his weakness in the affair with his father's wife.
“My firstborn, my might and the beginning of my generative power.” As the firstborn son, the first product of Jacob's strength, he was the one of whom much was expected. He was set to be Jacob's right hand. But he failed.
“Pre-eminent in dignity, pre-eminent in strength.” He was more contained than his brothers, and bore himself well and as the eldest was strongest.
“Uncontrolled as water, you will not be pre-eminent.” But he had a fatal flaw, he was unreliable, uncontrolled like a flow of surging water. Thus he could not safely take the pre-eminence, and, as we have seen, his place as leader has been taken by Judah. (The verb means ‘unstable, uncontrolled, frothing over').
“Because you went up to your father” s bed, then you defiled it ---'. This refers, of course, to when he went in to his father's concubine (Genesis 35:22). This too was a sign of his unreliability. He who should have watched over his father's bed defiled it. Thus he cannot be trusted.
He had his good points. He had tried to save Joseph and at least saved him from death, although he was not strong enough to stand up to his brothers. He was the one who was concerned about Simeon and wanted to go back for him, but he failed to persuade Jacob to let him take Benjamin. It was Judah who was firm and later succeeded. Perhaps even then his failure was because his father saw him as unreliable and untrustworthy.
Interestingly the tribe of Reuben also failed early. It is depicted by Moses as dying (Deuteronomy 33:6) and is mentioned with censure in Judges 5:15 where their inability to make a strong decision is emphasised. These ideas may have partly arisen from this original perception of Reuben.