When Israel joined themselves to Baal-peor, ¹  the anger of the Lord flared up against Israel.

So Moses said to the judges of Israel, “Each of you must execute those of his men ¹  who were joined to Baal-peor.”

because they bring trouble to you by their treachery with which they have deceived ¹  you in the matter of Peor, and in the matter of Cozbi, the daughter of a prince of Midian, ²  their sister, who was killed on the day of the plague that happened as a result of Peor.”

Look, these people through the counsel of Balaam caused the Israelites to act treacherously against the Lord in the matter of Peor – which resulted in the plague among the community of the Lord!