1 tn The Hebrew noun פַּחַז (pakhaz) only occurs here in the OT. A related verb occurs twice in the prophets (Jer 23:32; Zeph 3:4) for false prophets inventing their messages, and once in Judges for unscrupulous men bribed to murder (Judg 9:4). It would describe Reuben as being “frothy, boiling, turbulent” as water. The LXX has “run riot,” the Vulgate has “poured out,” and Tg. Onq. has “you followed your own direction.” It is a reference to Reuben’s misconduct in Gen 35, but the simile and the rare word invite some speculation. H. Pehlke suggests “destructive like water,” for Reuben acted with pride and presumption; see his “An Exegetical and Theological Study of Genesis 49:1-28” (Th.D. dissertation, Dallas Theological Seminary, 1985).
2 tn Heb “Do not excel!” The Hiphil of the verb יָתַר (yatar) has this meaning only here. The negated jussive is rhetorical here. Rather than being a command, it anticipates what will transpire. The prophecy says that because of the character of the ancestor, the tribe of Reuben would not have the character to lead (see 1 Chr 5:1).
3 sn This is a euphemism for having sexual intercourse with Jacob’s wives (see Gen 35:22).
4 tn The last verb is third masculine singular, as if for the first time Jacob told the brothers, or let them know that he knew. For a discussion of this passage see S. Gevirtz, “The Reprimand of Reuben,” JNES 30 (1971): 87-98.