Nehemiah 10:30

and that we would not give our daughters to the peoples of the land, nor take their daughters for our sons:

Exodus 34:16

and thou take of their daughters unto thy sons, and their daughters go a whoring after their gods, and make thy sons go a whoring after their gods.

Deuteronomy 7:3

And thou shalt make no marriages with them: thy daughter thou shalt not give unto his son, nor take his daughter for thy son;

Ezra 9:1-3

Now when these things were completed, the princes came to me, saying, The people of Israel, and the priests and the Levites, have not separated themselves from the peoples of the lands, according to their abominations, even of the Canaanites, the Hittites, the Perizzites, the Jebusites, the Ammonites, the Moabites, the Egyptians, and the Amorites;

Ezra 9:12-14

Now therefore give not your daughters to their sons, neither take their daughters to your sons, nor seek their peace or their prosperity for ever; that ye may be strong, and eat the good of the land, and leave it for an inheritance to your children for ever.

Ezra 10:10-12

And Ezra the priest stood up and said to them, Ye have acted unfaithfully, and have taken foreign wives, to increase the trespass of Israel.

Treasury of Scripture Knowledge

Summary

And that we would not give our daughters unto the people of the land, nor take their daughters for our sons:

Bible References

General references

Exodus 34:16
and thou take of their daughters unto thy sons, and their daughters go a whoring after their gods, and make thy sons go a whoring after their gods.
Deuteronomy 7:3
And thou shalt make no marriages with them: thy daughter thou shalt not give unto his son, nor take his daughter for thy son;
Ezra 9:1
Now when these things were completed, the princes came to me, saying, The people of Israel, and the priests and the Levites, have not separated themselves from the peoples of the lands, according to their abominations, even of the Canaanites, the Hittites, the Perizzites, the Jebusites, the Ammonites, the Moabites, the Egyptians, and the Amorites;
Ezra 10:10
And Ezra the priest stood up and said to them, Ye have acted unfaithfully, and have taken foreign wives, to increase the trespass of Israel.