Numbers 1:2-4
Numbers 1: 2 to 4
2 "Take a census of the entire Israelite community by their clans and their ancestral houses, counting the names of every male one by one.
3 You and Aaron are to register those who are 20 years old or more by their military divisions-- everyone who can serve in Israel's army.
4 A man from each tribe is to be with you, each one the head of his ancestral house.