Numbers 36:6

and so Jehovah says that the daughters of Zelophehad are free to marry anyone they wish but only within their own tribe.

Genesis 24:57-58

They answered: Let us call her and find out what she has to say.

Numbers 36:12

They married within the families of the descendants of Manasseh, son of Joseph. So their land stayed in the tribe of their father's family.

Genesis 24:3

I want you to swear by Jehovah God of heaven and earth that you will not get my son a wife from the daughters of the Canaanites among whom I am living.

2 Corinthians 6:14

Do not be unequally yoked with unbelievers: for what fellowship does righteousness have with lawlessness? Or what communion does light have with darkness?

Treasury of Scripture Knowledge

Summary

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.

Bible References

Only to the family

Numbers 36:12
They married within the families of the descendants of Manasseh, son of Joseph. So their land stayed in the tribe of their father's family.
Genesis 24:3
I want you to swear by Jehovah God of heaven and earth that you will not get my son a wife from the daughters of the Canaanites among whom I am living.
2 Corinthians 6:14
Do not be unequally yoked with unbelievers: for what fellowship does righteousness have with lawlessness? Or what communion does light have with darkness?