Numbers 1:3-5

Young's Literal Translation

³ from a son of twenty years and upward, every one going out to the host in Israel, ye do number them by their hosts, thou and Aaron;

⁴ and with you there is a man for a tribe, each is a head to the house of his fathers.

⁵ `And these [are] the names of the men who stand with you: `For Reuben -- Elizur son of Shedeur.