Numbers 1:3
from 20 years and upward. You and Aaron are to register everyone in Israel who is able to go to war, company by company.
Exodus 30:14
All who are registered, 20 years of age and older, are to give a contribution to the LORD.
Numbers 14:29
Your corpses will fall in this wilderness every single one of you who has been counted among you, according to your number from 20 years and above, who complained against me.
Exodus 12:17
""You are to observe the Festival of Unleavened Bread, since on this very day I brought your tribal divisions from the land of Egypt. You are to observe this day from generation to generation as a perpetual ordinance.
Numbers 26:2
"Take a census of the entire community of Israel from the age of 20 years and above, according to each ancestral tribe, counting everyone who is able to go out to war in Israel."
Numbers 32:11
"Not one of the men who went up from Egypt, from 20 years old and above, will see the land that I promised to give to their ancestors, that is, to Abraham, Isaac, and Jacob, because none of them followed me wholeheartedly,
Numbers 33:1
Here's the travel itinerary for the Israelis after they left the land of Egypt in groups under the authority of Moses and Aaron.
Deuteronomy 3:18
"Then I commanded you at that time, "The Lord your God gave you this land as a possession. Those equipped for battle every man a warrior will cross before your fellow Israelis.
Deuteronomy 24:5
"When a man is newly married, he must not be sent out to war or have a related duty placed on him. Let him stay home for one year and be happy with his wife whom he has married.
2 Samuel 24:9
Joab reported the total number of men to the king. In Israel there were 800,000 men trained for war. In Judah there were 500,000.
2 Chronicles 17:13-18
He placed a large amount of supplies into storage throughout the cities of Judah and stationed soldiers all of them valiant men in Jerusalem.
2 Chronicles 26:11-13
Uzziah kept a standing army, equipped for battle, garrisoned in divisions according to an organizational structure devised by his royal secretary Jeiel and his officer Maaseiah, who reported to Hananiah, one of the king's commanders.