Bamidbar 26:1-2

Orthodox Jewish Bible

26 And it came to pass after the magefah (plague), that Hashem spoke unto Moshe and unto Eleazar Ben Aharon HaKohen, saying,

² Take the rosh (census) of kol Adat Bnei Yisroel from twenty years old and upward, throughout their bais avot, all that are yotzei tzava (able to go to war) in Yisroel.