Adam Clarke on Numbers 27:1

The daughters of Zelophehad - The singular case of these women caused an additional law to be made to the civil code of Israel, which satisfactorily ascertained and amply secured the right of succession in cases of inheritance. The law, which is as reasonable as it is just, stands thus:

1. On the demise of the father the estate goes to the sons;

2. If there be no son, the daughters succeed; 3. If there be no daughter, the brothers of the deceased inherit;

4. If there be no brethren or paternal uncles, the estate goes to the brothers of his father;

5. If there be no grand uncles or brothers of the father of the deceased, then the nearest akin succeeds to the inheritance.

Beyond the fifth degree the law does not proceed, because as the families of the Israelites were kept distinct in their respective tribes, there must always be some who could be called kinsmen, and were really such, having descended without interruption from the patriarch of the tribe.