Numbers 26:36

And it came to pass after the plague, that the LORD spake unto Moses and unto Eleazar the son of Aaron the priest, saying,

Take the sum of all the congregation of the children of Israel, from twenty years old and upward, throughout their fathers' house, all that are able to go to war in Israel.

And Moses and Eleazar the priest spake with them in the plains of Moab by Jordan near Jericho, saying,

Take the sum of the people, from twenty years old and upward; as the LORD commanded Moses and the children of Israel, which went forth out of the land of Egypt.

Reuben, the eldest son of Israel: the children of Reuben; Hanoch, of whom cometh the family of the Hanochites: of Pallu, the family of the Palluites: