Numbers 1:16

16. Heads of thousands in Israel This language sounds so much like Exodus 18:21 that it is probable that the assistant judges, carefully chosen by Moses at the suggestion of Jethro his father-in-law, were named by the Lord associates of Moses and Aaron in completing the registration. The Hebrew for the renowned of the congregation is, the called of the congregation, a select number, suggesting a representative body, to whom Moses often spoke when it is said that he addressed all the congregation. “The social condition of the Israelites in the wilderness bore a close resemblance to that of the nomad tribes of the East in the present day. The head of the tribe was an hereditary dignity, vested in the eldest son, or some other to whom the right of primogeniture was transferred, and under whom were other inferior heads, also hereditary.” Jamieson.