And thou shalt write Aaron's name upon the rod of Levi
Or upon the rod that was for the tribe of Levi; the name of "Aaron" was to be written, not the word "Levi", or a "Levite", as Josephus F5; for that would not have decided the controversy about the priesthood, which chiefly lay between the Levites and the family of Aaron, who were of the same tribe:
for one rod [shall be] for the head of the house of their fathers;
one rod for the head or prince of every tribe, every prince representing his own tribe he was the head of, and the rod the prince; and though the tribe of Levi was divided into two families, the family of the priests, and the family of the Levites; yet, as Jarchi observes, they were but one tribe, and so one rod for them, as for the other tribes.
F5 Antiqu. l. 4. c. 4. sect. 2.