Números 25:18

18 They treated you as enemies when they deceived you in the Peor incident involving their sister Kozbi, the daughter of a Midianite leader, the woman who was killed when the plague came as a result of that incident."

18 for they vex you with their wiles, wherewith they have beguiled you in the matter of Peor, and in the matter of Cozbi, the daughter of the prince of Midian, their sister, who was slain on the day of the plague in the matter of Peor.