Nehemiah 10:30
"We will not give our daughters in marriage to the neighboring peoples, and we will not take their daughters in marriage for our sons.
Exodus 34:16
and you then take his daughters for your sons, and when his daughters prostitute themselves to their gods, they will make your sons prostitute themselves to their gods as well.
Deuteronomy 7:3
You must not intermarry with them. Do not give your daughters to their sons or take their daughters for your sons,
Ezra 9:1-3
Now when these things had been completed, the leaders approached me and said, "The people of Israel, the priests, and the Levites have not separated themselves from the local residents who practice detestable things similar to those of the Canaanites, the Hittites, the Perizzites, the Jebusites, the Ammonites, the Moabites, the Egyptians, and the Amorites.
Ezra 9:12-14
Therefore do not give your daughters in marriage to their sons, and do not take their daughters in marriage for your sons. Do not ever seek their peace or welfare, so that you may be strong and may eat the good of the land and may leave it as an inheritance for your children forever.'
Ezra 10:10-12
Then Ezra the priest stood up and said to them, "You have behaved in an unfaithful manner by taking foreign wives! This has contributed to the guilt of Israel.