Numbers 31:1-6

1The Lord spoke to Moses, saying,

2"Avenge the people of Israel on the Midianites. Afterward you shall be gathered to your people."

3So Moses spoke to the people, saying, "Arm men from among you for the war, that they may go against Midian to execute the Lord's vengeance on Midian.

4You shall send a thousand from each of the tribes of Israel to the war."

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

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