Numbers 1:3

1:3 You and Aaron are to number all in Israel who can serve in the army, those who are twenty years old or older, by their divisions.

Numbers 10:25

10:25 The standard of the camp of the Danites set out, which was the rear guard of all the camps by their companies; over his company was Ahiezer son of Ammishaddai.

Numbers 31:6

Campaign Against the Midianites

31:6 So Moses sent them to the war, one thousand from every tribe, with Phinehas son of Eleazar the priest, who was in charge of the holy articles and the signal trumpets.