Numbers 31:1-3 Darby Translation (DARBY)
31 And Jehovah spoke to Moses, saying,
2 Avenge the children of Israel upon the Midianites; afterwards shalt thou be gathered unto thy peoples.
3 And Moses spoke to the people, saying, Arm from amongst you men for military service, that they go against Midian to execute Jehovah's vengeance upon Midian.
Numbers 31:1-3 New International Version (NIV)
Vengeance on the Midianites
31 The Lord said to Moses, 2 “Take vengeance on the Midianites for the Israelites. After that, you will be gathered to your people.”
3 So Moses said to the people, “Arm some of your men to go to war against the Midianites so that they may carry out the Lord’s vengeance on them.