Numbers 31:3-5

Revised Geneva Translation

³ And Moses spoke to the people, saying, “Some of you, arm yourselves for war. And let them go against Midian, to execute the vengeance of the LORD against Midian.

⁴ “A thousand of every tribe throughout all the tribes of Israel shall you send to the war.”

⁵ So there were taken out of the thousands of Israel, twelve thousand, prepared to war, of every tribe a thousand.