On the first day of the second month of the second year after the exodus from Egypt, the Lord speaks to Moses in the tent of meeting in the wilderness of Sinai. He commands him to count the whole congregation by clans and fathers' houses, listing by name every man twenty years old and up who can go out to war. One man from each tribe, the head of his father's house, will assist Moses and Aaron, and the text records their names.
Moses and Aaron gather the congregation and take the census just as the Lord commanded. The chapter reviews the result tribe by tribe: Reuben, Simeon, Gad, Judah, Issachar, Zebulun, the sons of Joseph (Ephraim and Manasseh), Benjamin, Dan, Asher and Naphtali. The total of those counted comes to 603,550 men.
The tribe of Levi stands apart. The Lord orders that it not be counted with the rest but be put in charge of the tabernacle of the testimony, its furnishings and its service: the Levites will carry it, set it up and take it down, and they will camp around it so that God's wrath does not fall on the congregation. Any outsider who comes near will die. The Israelites camp, each under his own banner, and the chapter ends with a line of obedience: they did everything just as the Lord commanded Moses.