John Gill Commentary Numbers 1:4

"And with you there shall be a man of every tribe; every one head of his fathers` house." — Numbers 1:4 (ASV)

And with you there shall be a man of every tribe
Excepting Levi, of which Moses and Aaron were, to assist in taking the account, and to see that it was an exact and perfect one:

everyone head of the house of his fathers ;
and prince of the tribe he belonged to, as appears from (Numbers 1:16) and (Numbers 7:2) , where an account is given of the same persons as princes of the tribes that offered at the dedication of the altar, who here assisted in the taking this account; the Targum of Jonathan calls them each a prince, as Prince Elizur