Numbers 26:1-4

And it came to pass, after the plague, that the LORD spoke to Moses and Eleazar the son of Aaron the priest, saying: “Take a census of all the congregation of the children of Israel from twenty years old and above, by their fathers’ houses, all who are able to go to war in Israel.” So Moses and Eleazar the priest spoke with them in the plains of Moab by the Jordan, across from Jericho, saying: “Take a census of the people from twenty years old and above, just as the LORD commanded Moses and the children of Israel who came out of the land of Egypt.”