Numbers 1:18

18 and gathered the whole congregation together on the first day of the second month. The people registered themselves in their tribes according to their ancestral families, putting down the names of those who were twenty years old and older,

Numbers 1:18 In-Context

16 These were the men chosen from the congregation, leaders of their ancestral tribes, heads of Israel's military divisions.
17 Moses and Aaron took these men who had been named to help
18 and gathered the whole congregation together on the first day of the second month. The people registered themselves in their tribes according to their ancestral families, putting down the names of those who were twenty years old and older,
19 just as God commanded Moses. He numbered them in the Wilderness of Sinai.
20 The line of Reuben, Israel's firstborn: The men were counted off head by head, every male twenty years and older who was able to fight in the army, registered by tribes according to their ancestral families.
Published by permission. Originally published by NavPress in English as THE MESSAGE: The Bible in Contemporary Language copyright 2002 by Eugene Peterson. All rights reserved.