Thou art poured out as water, grow thou not: because thou wentest up to thy father’s bed, and didst defile his couch.

“See how through the insight granted him by the Spirit Jacob anticipates the legislation of Moses against allowing father and son to have relations with the same woman. Ahead of time he forbids this in censuring his son thus, "You stained the couch" by entering your father's bed. You committed an unlawful act, he says. Hence "you ran riot like water, but you shall not break out again."”

“פחז כמים The impetuosity and the precipitance with which you so hastily showed your wrath, just like water that rushes headlong in its course — therefore אל תותר THOU SHALT NOT BE SUPERIOR— you will not receive all these many prerogatives that were proper to you. And what was this impetuosity which you displayed? כי עלית משכבי אביך, אז חללת BECAUSE THOU WENTEST UP TO THY FATHER S PLACE OF REPOSE; THEN PROFANEDST THOU Him Who hovered over my couch — the Name of the Shechina that used to abide above my couch (Shabbat 55b and Rashi there). פַּחַז is a noun (a segolate noun like נַחַל) and has its accent therefore on the first syllable, and the entire word (both syllables) is punctuated with Patach, for were it the past tense of a verb, half of it (the first syllable) would have been punctuated with Kametz and the other half with Patach, and its accent would have been on the last syllable. יצועי denotes a couch, because it is spread (root יצע) with mattresses and sheets; it occurs in this sense frequently in Scripture: (Psalms 132:3) “Nor go up into the bed that is spread for me (ערש יצועי)” ; (Psalms 63:7) “When I remember thee upon my (יצועי) couch”.”

“UNSTABLE (‘PACHAZ’) AS WATER, YOU HAVE NOT THE EXCELLENCY. Pachaz is a noun, derived from the expression, Vain and reckless (‘upachazim’) fellows, meaning “hasty and impulsive people.” Our Rabbis have made steady use of this word: “I was looking at my image in the water and my evil inclination rose (pachaz) within me,” that is “my evil inclination leaped upon me” They said further: “It is their recklessness (apichzeihu) which they are revealing,” meaning their impulsiveness. “A reckless (p’chizah) people, who spoke before listening, you still retain your recklessness (‘b’pachzuteich’),” meaning “hasty and impulsive.” It is possible that this word pachaz is a permutation of the word chipazon (hurry). and kesev, both of which mean “lamb,” and other similar words. Jacob was thus saying: “Since you burst forth as water, you shall no longer excel for thou wentest up to thy father’s place of repose in thy haste and impulsiveness. Then didst thou profane them, (places of repose), which is in the plural form. Hence Ramban writes otham (them). when your recklessness ascended my couch like the rising and gushing water.” This is similar to the Scriptural description of water: Now, therefore, behold, the Lord bringeth up upon them the waters of the river, mighty and many, even the king of Assyria and all his glory; and he shall come up over all his channels, and go over all his banks; and he shall sweep through Judah, overflowing as he passeth through. Our Rabbis have said: “Then didst thou profane He Who hovered over my couch, meaning the Shechinah” that used to abide above my [Jacob’s] couch. Yet the verse says, Forasmuch as he [Reuben] defiled his father’s couch,. Ramban proceeds to answer that Scripture modifies the expression out of respect for the Divine Presence. thus clearly stating that it was the couch which was defiled! But perhaps [out of respect for the Divine Presence, Scripture] modifies the expression there. But if [we accept the explanation that Scripture modifies the expression], it is possible that the word alah (going up) refers to [Jacob, thus saying, “then didst thou profane my couch upon which I used to go up],” just as in the verse, Nor go up into the bed that is spread for me. Thus Jacob’s intent is to say: “Then thou didst defile me;” He spoke in the third person, “he” went up. only as a matter of respect. Similarly, the verse, Forasmuch as he defiled his father’s couch, is a Scriptural modification, meaning “forasmuch as he [Reuben] defiled the one who goes up upon his father’s couch.” From the literal meaning of this verse it would appear as I have explained it in Seder Vayishlach, i.e., that it was Reuben’s intention to disqualify Bilhah from his father so that she should no longer give birth to children, thus lessening his share as the firstborn. It was for this reason that Jacob said to him that it was reckless and impulsive to think that he would gain thereby, whereas he had no profit from it but only loss.”

“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 Deu 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, Gen 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, Psa 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.”

“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 Jdg 9:4; Zep 3:4; Jer 23:14, Jer 23:32; Jer 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 Dan, when Moses took the sum of them in the wilderness, Num 1:21; and was among the first that were carried into captivity, Ch1 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 Gen 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.”

“Grow thou not. This was not meant by way of a curse or imprecation; but by way of a prophecy, foretelling that the tribe of Ruben should not inherit the pre-eminences usually annexed to the first birth-right, viz., the double portion, the being prince or lord over the other brethren, and the priesthood: of which the double portion was given to Joseph, the princely office to Juda, and the priesthood to Levi. (Challoner) — Thou hast abandoned thyself to thy brutal passion; do so no more, ne adjicias. (St. Jerome, q. Heb.) Let Ruben live, and die not; let him be small in number, Deuteronomy xxxiii. 6. His tribe never became very considerable. (Calmet) — Couch. See chap xxxv. 22. Eternal infamy attends the name of Ruben. (Haydock)”