16These were famous men of the congregation, heads of the tribes according to their families: these are heads of thousands in Israel.
17And Moses and Aaron took these men who were called by name.
18And they assembled all the congregation on the first day of the month in the second year; and they registered them after their lineage, after their families, after the number of their names, from twenty years old and upwards, every male according to their number:
Numbers 1
Numbers 1:16-18