Numbers 36:6
This is the thing which the LORD doth command concerning the daughters of Zelophehad, saying, Let them marry to whom they think best; only to the family of the tribe of their father shall they marry. This is the thing which the LORD doth command concerning the daughters of Zelophehad, saying, Let them marry to whom they think best; only to the family of the tribe of their father shall they marry.
The command concerns the laws governing daughters' inheritance, permitting the daughters of Zelophehad to marry whom they chose or thought best, yet requiring that choice to remain within the family of their father's tribe. That limitation kept inherited land within that tribe, forming part of the directions protecting the inheritance of the tribes. In this way the restriction belonged to the law preserving landed property in connection with the Jubilee.