Numbers 36:6-9

6This is what the LORD has commanded concerning the daughters of Zelophehad: They may marry anyone they please, provided they marry within a clan of the tribe of their father. 7No inheritance in Israel may be transferred from tribe to tribe, because each of the Israelites is to retain the inheritance of the tribe of his fathers. 8Every daughter who possesses an inheritance from any Israelite tribe must marry within a clan of the tribe of her father, so that every Israelite will possess the inheritance of his fathers. 9No inheritance may be transferred from one tribe to another, for each tribe of Israel must retain its inheritance.”