Numbers 1:3-5
Numbers 1: 3 to 5
3 You and Aaron are to muster by their divisions every son from 20 years and upward available to serve in the army of Israel.
4 One man from each tribe, each head of his father’s household, is to assist you.
5 “These then are the names of the men who will assist you: from Reuben, Elizur son of Shedeur.