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.

Numbers 36:8

36:8 And every daughter who possesses an inheritance from any of the tribes of the Israelites must become the wife of a man from any family in her father’s tribe, so that every Israelite may retain the inheritance of his fathers.