Unstable as water. He shows that the honor which had not a good conscience for its keeper, was not firm but evanescent; and thus he rejects Reuben from the primogeniture. He declares the cause, lest Reuben should complain that he was punished when innocent: for it was also of great consequence, in this affair, that he should be convinced of his fault, lest his punishment should not be attended with profit. We now see Jacob, having laid carnal affection aside, executing the office of a prophet with vigor and magnanimity. For this judgment is not to be ascribed to anger, as if the father desired to take private vengeance of his son: but it proceeded from the Spirit of God; because Jacob kept fully in mind the burden imposed upon him. The word lch (alach) the close of the sentence signifies to depart, or to be blown away like the ascending smoke, which is dispersed. [1] Therefore the sense is, that the excellency of Reuben, from the time that he had defiled his father's bed, had flowed away and become extinct. For to expound the expression concerning the bed, to mean that it ceased to be Jacob's conjugal bed, because Bilhah had been divorced, is too frigid.

Footnotes

1 - The literal translation of Calvin's version is, "Thy velocity was like that of water, thou shalt not excel: because thou wentest up into thy father's couch, then thou pollutedst my bed, he has vanished." This gives the patriarch's expression a different turn from that supposed by our translators; who understand the last word in the sentence to be a repetition of what had been said before, only putting it in the third person, as expressive of indignation; as if he had turned round from Reuben to his other children and said -- "Yes, I declare he went up into my bed!" Another view is given in the margin of our Bible, "My couch is gone;" which means that, by this defilement, the marriage bond was broken. To this version Calvin objects at the close of the paragraph. But both these constructions seem forced. Calvin's appears the most natural. He represents Reuben as having lost all, by his criminal conduct. Honour, excellence, priority, virtue, and consequently character and influence, had all gone up as the dew from the face of the earth, and had vanished away. -- Ed.

Pouring out like the waters - This is an obscure sentence because unfinished. It evidently relates to the defilement of his father's couch; and the word פחז pachaz, here translated pouring out, and in our Version unstable, has a bad meaning in other places of the Scripture, being applied to dissolute, debauched, and licentious conduct. See Judges 9:4; Zephaniah 3:4; Jeremiah 23:14, Jeremiah 23:32; Jeremiah 29:23.
Thou shalt not excel - This tribe never rose to any eminence in Israel; was not so numerous by one third as either Judah, Joseph, or Daniel, when Moses took the sum of them in the wilderness, Numbers 1:21; and was among the first that were carried into captivity, 1-Chronicles 5:26.
Then thou didst defile - Another unfinished sentence, similar to the former, and upon the same subject, passing over a transaction covertly, which delicacy forbade Jacob to enlarge on. For the crime of Reuben, see Clarke on Genesis 35:22 (note).
5. Simeon and Levi, brethren: They have accomplished their fraudulent purposes.
6. Into their secret council my soul did not come; In their confederacy my honor was not united: For in their anger they slew a man, (איש ish, a noble), And in their pleasure they murdered a prince.
7. Cursed was their anger, for it was fierce! And their excessive wrath, for it was inflexible! I will divide them out in Jacob, And I will disperse them in Israel.

Unstable as water,.... Which is not to be understood of the levity of his mind, and his disposition to hurt, and the impetuous force of that breaking forth like water, and carrying him into the commission of it; but rather of his fall from his excellency and dignity, like the fall of water from an high place; and of his being vile, mean, and contemptible, useless and unprofitable, like water spilled on the ground; and of his weak and strengthless condition and circumstances, being deprived of the prerogatives and privileges of his birthright, and having lost all his honour and grandeur, power and authority. The word in the Arabic language signifies (b) to be proud and haughty, to lift up one's self, to swell and rise like the turgent and swelling waters: but though he did thus lift himself, yet it follows:
thou shall not excel; not have the excellency of dignity and power which belonged to him as the firstborn; the birthright and the double portion were given to Joseph, who had two tribes descending from him, when Reuben had but one; the kingdom was given to Judah, and the priesthood to Levi, as both the Targums of Jonathan and Jerusalem observe: as he did not excel his brethren in honour and dignity, so neither in wealth and riches, nor in numbers; see Deuteronomy 33:6 where the word "not" is wrongly supplied; nor in his share in the land of Canaan, his posterity being seated on the other side of Jordan, at their request; nor did any persons of note and eminence spring from his tribe: because thou wentest up to thy father's bed, then defiledst thou it; referring to his incest with Bilhah, his father's concubine wife, Genesis 35:22 which, though done forty years ago, was now remembered, and left an indelible spot on Reuben's character, and his posterity:
he went up to my couch: turning himself to his other sons, to take notice of the crime, as very abominable and detestable; affirming the truth of it, and speaking of it with some vehemency, his affections being moved; and it may be could not bear to look at Reuben, but turned himself to his brethren; though he had forgiven the sin, and very probably Reuben had repented of it, and had forgiveness of God, which he might have, though in some sense vengeance was taken on this sinful invention of his, Psalm 99:8. There are various senses given of this phrase; some, as Aben Ezra, "my bed departed from me"; that is, he departed from his bed; or, as Kimchi (c), "it ceased to be my bed"; he left it, he abstained from the bed of Bilhah upon its being defiled by Reuben: and others separate these words, and read singly, "it went up" (d); either the excellency of Reuben went up, vanished and disappeared like smoke; or, as Ben Melech connects it with the beginning of the verse, "unstable as water", giving the sense, "it", the inundation of water, "ascended" and prevailed over thee; as waters ascend, meaning his lust ascended, and got the prevalence over him; but the accents will not admit of such a separation of the words; it is best to understand them in the first sense. As to the manner of the expression, of going up to a bed, it may be observed, that not only their beds in those times might be raised higher than ours, but that they were placed in an higher part of the room, and so there was an ascent to them: and Dr. Shaw (e) says this is the custom of the eastern people to this day,"at one end of each chamber there is a little gallery, raised three, four, or five feet above the floor, with a balustrade in the front of it, with a few steps likewise leading up to it, here they place their beds.''
(b) "superbivit, semet extulit gloria fastuque", Golius, col. 1767. so Castel. col. 2980. (c) Sepher Shorash. rad. (d) "ascendit", i.e. "abiit" "et evanuit", Vatablus. (e) Travels, p. 209. Ed. 2.

Thou shalt not excel - A being thou shalt have as a tribe, but not an excellency. No judge, prophet, or prince, are found of that tribe, nor any person of renown only Dathan and Abiram, who were noted for their impious rebellion. That tribe, as not aiming to excel, chose a settlement on the other side Jordan. The character fastened upon Reuben, for which he is laid under this mark of infamy, is, that he was unstable as water. His virtue was unstable, he had not the government of himself, and his own appetites. His honour consequently was unstable, it vanished into smoke, and became as water spilt upon the ground. Jacob charges him particularly with the sin for which he was disgraced, thou wentest up to thy father's bed - It was forty years ago that he had been guilty of this sin, yet now it is remembered against him. Reuben's sin left an indelible mark of infamy upon his family; a wound not to be healed without a scar.