Numbers 31:3-5

New King James Version

³ So Moses spoke to the people, saying, “Arm some of yourselves for war, and let them go against the Midianites to take vengeance for the Lord on ^(A)Midian. ⁴ A thousand from each tribe of all the tribes of Israel you shall send to the war.”

⁵ So there were recruited from the divisions of Israel one thousand from each tribe, twelve thousand armed for war.