Numbers 25:3

25:3 When Israel joined themselves to Baal-peor, the anger of the Lord flared up against Israel.

Numbers 25:5

25:5 So Moses said to the judges of Israel, “Each of you must execute those of his men who were joined to Baal-peor.”

Numbers 25:18

25:18 because they bring trouble to you by their treachery with which they have deceived you in the matter of Peor, and in the matter of Cozbi, the daughter of a prince of Midian, their sister, who was killed on the day of the plague that happened as a result of Peor.”