Numbers 36:6

This is the thing which Jehovah doth command concerning the daughters of Zelophehad, saying, Let them be married to whom they think best; only into the family of the tribe of their father shall they be married.

Genesis 24:57-58

And they said, We will call the damsel, and inquire at her mouth.

Numbers 36:12

They were married into the families of the sons of Manasseh the son of Joseph; and their inheritance remained in the tribe of the family of their father.

Genesis 24:3

And I will make thee swear by Jehovah, the God of heaven and the God of the earth, that thou wilt not take a wife for my son of the daughters of the Canaanites, among whom I dwell.

2 Corinthians 6:14

Be not unequally yoked with unbelievers: for what fellowship have righteousness and iniquity? or what communion hath light 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 were married into the families of the sons of Manasseh the son of Joseph; and their inheritance remained in the tribe of the family of their father.
Genesis 24:3
And I will make thee swear by Jehovah, the God of heaven and the God of the earth, that thou wilt not take a wife for my son of the daughters of the Canaanites, among whom I dwell.
2 Corinthians 6:14
Be not unequally yoked with unbelievers: for what fellowship have righteousness and iniquity? or what communion hath light with darkness?

American Standard Version Public Domain