Numbers 31:3-5

Revised Standard Version

³ And Moses said to the people, “Arm men from among you for the war, that they may go against Mid′ian, to execute the Lord’s vengeance on Mid′ian. ⁴ You shall send a thousand from each of the tribes of Israel to the war.” ⁵ So there were provided, out of the thousands of Israel, a thousand from each tribe, twelve thousand armed for war.