Numbers 1:3 in the World English Bible
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.
Context
2 Take ye the sum of all the congregation of the children of Israel, after their families, by the house of their fathers, with the number of their 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 armies.
4 And with you there shall be a man of every tribe; every one head of the house of his fathers.