Numbers 1:2-4

American Standard Version

² Take ye the sum of all the congregation of the children of Israel, by their families, by their fathers’ houses, according to the number of the names, every male, by their polls; ³ from twenty years old and upward, all that are able to go forth to war in Israel, thou and Aaron shall number them by their hosts. ⁴ And with you there shall be a man of every tribe; every one head of his fathers’ house.