Numbers 36:6 (BSB)

This 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.

From Numbers 36. Also in the ESV.

Commentary on Numbers 36:6

• Matthew Henry (Presbyterian), Matthew Henry's Complete Commentary on Numbers 36:5-13: Here is, I. The matter settled by express order from God between the daughters of Zelophehad and the rest of the tribe of Manasseh. The petition is assented to, and care taken to prevent the inconvenience feared: The tribe of the sons of Joseph hath said well, Num 36:5.
• John Gill (Reformed Baptist), Exposition of the Old and New Testaments on Numbers 36:6: This is the thing which the Lord doth command concerning the daughters of Zelophehad,.... Concerning this affair relative to them; the Targum of Jonathan paraphrases the words,"not for the generations that rise up after the division of the land, but for the daughters of Zelophehad;''as if this order only respected them, or what might happen before the land was divided, but not after; and this...
• Adam Clarke (Methodist), Clarke's Commentary on the Bible on Numbers 36:6: Let them marry to whom they think best - Here was latitude sufficient, and yet a salutary and reasonable restraint, which prevented a vexatious mixture of property and possession.
• Keil & Delitzsch (Lutheran), Biblical Commentary on the Old Testament on Numbers 36:5-9: Num 36:5-9 Moses declared that what they had affirmed was right (כּן), and then, by command of Jehovah, he told the daughters of Zelophehad that they might marry whoever pleased them (the suffix ־הם, attached to בּעיני, for ־הן, as in Exo 1:21; Gen 31:9, etc.), but that he must belong to the family of their father’s tribe, that is to say, must be a Manassite.