Numbers 1:3 in the King James Version
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 armies.
Context
2 “Take a census 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, one by one,
3 from twenty years old and upward, all who are able to go out to war in Israel. You and Aaron shall count them by their divisions.
4 With you there shall be a man of every tribe, each one head of his fathers’ house.