Numbers 31:3-5

New Revised Standard Version, Anglicised Catholic Edition

³ So Moses said to the people, ‘Arm some of your number for the war, so that they may go against Midian, to execute the Lord’s vengeance on Midian. ⁴ You shall send a thousand from each of the tribes of Israel to the war.’ ⁵ So out of the thousands of Israel, a thousand from each tribe were conscripted, twelve thousand armed for battle.