Numbers 25:14-18

14And the name of the man of Israel that was slain, who was slain with the Midianitish woman, was Zimri, the son of Salu, the prince of a father's house of the Simeonites. 15And the name of the Midianitish woman that was slain was Cozbi, the daughter of Zur; he was tribal head of a father's house in Midian. 16And Jehovah spoke to Moses, saying, 17Harass the Midianites, and smite them, 18for they have harassed you with their wiles, wherewith they have beguiled you in the matter of Peor, and in the matter of Cozbi, the daughter of a prince of Midian, their sister, who was slain on the day of the plague because of the matter of Peor.