Thou shalt write Aaron's name upon the rod of Levi. There was no tribe prince of Levi, and it is not probable that either of the three chiefs of the sub-tribes (Numbers 3:24, Numbers 3:30, 55) was called upon to bring a rod.
This rod was, therefore, provided by Moses himself, and inscribed by him with the name of Aaron, who stood by Divine appointment (so recently and fearfully attested) above all his brethren. For the significance of the act cf.
Ezekiel 37:16-28. For one rod … for the head of the house of their fathers. For Levi, therefore, there must be, not three rods inscribed with the names of the chiefs, but one only bearing the name of Aaron, as their common superior.