Charles Ellicott Commentary Numbers 36

And when the jubile of the children of Israel shall be. —Up to the year of jubile it was possible that the inheritance might revert to the tribe of Manasseh, either by purchase, or as the result of the marriages of the daughters proving childless. At the jubile the transfer of the inheritance to the tribe or tribes into which the daughters of Zelophehad might have married would become permanent.

And Moses commanded the children of Israel according to the word of the Lord.— In regard to the application made by the daughters of Zelophehad to Moses and Eleazar and the princes, it is said that Moses brought their cause before the Lord (Numbers 27:5). In the present case there is no express declaration made to the same effect; but there can be no doubt that the statement contained in this verse, that Moses commanded the children of Israel according to the word of the Lord, and that contained in Numbers 36:6, This is the thing which the Lord doth command, imply that Moses had committed this cause also to the Lord, and that he had received direction from Him.

And every daughter, that possesses an inheritance ... — The particular direction which was given in the case of the daughters of Zelophehad is extended in these verses into a general and permanent law that no heiress in Israel should marry out of her father’s tribe, in order that the inheritance might not be transferred from one tribe to another, and thus, in the course of time, the division of the land among the tribes, which was made under Divine direction, be materially changed.

Were married unto their father’s brothers’ sons. —Better, to the sons of their near kinsmen. The word dod generally denotes an uncle on the father’s side, and probably does so in the present case; but in Jeremiah 32:12 it seems to denote a cousin.