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.”

Numbers 36:3

36:3 Now if they should be married to one of the men from another Israelite tribe, their inheritance would be taken from the inheritance of our fathers and added to the inheritance of the tribe into which they marry. As a result, it will be taken from the lot of our inheritance.