Numbers 31:3

¹  And the LORD spake unto Moses, saying,

²  Avenge the children of Israel of the Midianites: afterward shalt thou be gathered unto thy people.

³  And Moses spake unto the people, saying, Arm some of yourselves unto the war, and let them go against the Midianites, and avenge the LORD of Midian.

⁴  Of every tribe a thousand, throughout all the tribes of Israel, shall ye send to the war.

⁵  So there were delivered out of the thousands of Israel, a thousand of every tribe, twelve thousand armed for war.