Numbers 31:3-6 ▼

3 Moses spoke to the people, saying, “Arm men from among you for war, so that they may go against Midian to execute the LORD’S vengeance on Midian [for seducing Israel to participate in idolatry].

4 A thousand [fighting men] from each tribe of all the tribes of Israel you shall send to the war.”

5 So out of the thousands of Israel, a thousand from each tribe were selected, twelve thousand armed for war.

6 Moses sent them, a thousand from each tribe, to the war, and Phinehas the son of Eleazar the priest, to war with them, and the sacred vessels [of the sanctuary] and the trumpets to blow the alarm in his hand.