3 Reuben, thou art my firstborn, my might, and the beginning of my strength, the excellency of dignity, and the excellency of power:
4 Unstable as water, thou shalt not excel; because thou wentest up to thy father’s bed; then defiledst thou it: he went up to my couch.
Reuben, the firstborn, receives his blessing from Jacob. Jacob acknowledges the strength and dignity and excellency that Reuben began with, but for his crime of adultery he has lost his place. Jacob foretells that Reuben will not excel among his brethren, and this proves to be true. Reuben will never produce a king or a prophet, at least none that are noted in the biblical narrative.
Reuben will be part of the ten tribes that break off from Judah and will be taken captive by the Assyrians with the rest of the kingdom, more than seven hundred years before the birth of Christ. What happened to them after that is a matter of broad speculation, but as with most of the tribes there is no clear answer.