Targum zu Bereschit 49:3

Reuben thou art my firstborn, the beginning of the strength of my generation, and the chief event of my thoughts To thee belonged the birthright, and the high priesthood, and the kingdom: but because thou hast sinned, my son, the birthright is given to Joseph, and the, kingdom to Jehuda, and the priesthood to Levi.

REUBEN, my firstborn art thou, my strength, and the beginning of my sorrow. To thee my son Reuben would it have pertained to receive three portions above thy brethren, birthright, priesthood, kingdom: but because thou hast sinned, Reuben, my son, the birthright is given unto Joseph, the kingdom to Jehuda, and the high priesthood to the tribe of Levi.