Bamidbar 31:2-4

Orthodox Jewish Bible

² Avenge the Bnei Yisroel of the Midyanim; afterward shalt thou be gathered unto thy people.

³ And Moshe spoke unto HaAm, saying, Arm some of your anashim unto war, let them go against Midyan, and avenge Hashem of Midyan.

⁴ Of every matteh a thousand, throughout kol mattot Yisroel, shall ye send to war.