Nehemiah 13:23

I saw the Jews who were married to women of Ashdod and Ammon and Moab:

Nehemiah 10:30

That way we would not give our daughters to the peoples of the lands, or take their daughters for our sons;

Ezra 9:1-2

After these things were done, the captains came to me and said: The people of Israel and the priests and Levites have not kept themselves separate from the people of the lands. They have taken part in the disgusting ways of the Canaanites, the Hittites, the Perizzites, the Jebusites, the Ammonites, the Moabites, the Egyptians, and the Amorites.

Ezra 10:10

Ezra the priest got to his feet and said to them: You have done wrong and taken strange women for your wives, thus increasing the sin of Israel.

Nehemiah 13:1

On that day there was a reading from the book of Moses while the people listened. They heard that it said in the book that no Ammonite or Moabite might ever come into the meeting of God at any time.

1 Samuel 5:1

The Philistines captured the Ark of God and they brought it from Ebenezer to Ashdod.

Ezra 9:11-12

Which you gave to your servants the prophets, saying: 'The land where you are going, you should take for a heritage. It is an unclean land, because of the evil lives of the peoples of the land and their disgusting ways, which have made the land unclean from end to end.'

Ezra 10:44

All these had taken strange wives; and some of them had wives by whom they had offspring.

Nehemiah 4:7

When the Sanballat and Tobiah and the Arabians and the Ammonites and the Ashdodites, heard that the building of the walls of Jerusalem was going forward and the broken places were being made good, they were very angry.

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

In those days also saw I Jews that had married wives of Ashdod, of Ammon, and of Moab:

Bible References

Married

Nehemiah 10:30
That way we would not give our daughters to the peoples of the lands, or take their daughters for our sons;
Ezra 9:2
They have taken their daughters as wives for themselves and for their sons. They have mingled the holy race with peoples around them. In fact the leaders and officials were first to do this evil.
Ezra 10:10
Ezra the priest got to his feet and said to them: You have done wrong and taken strange women for your wives, thus increasing the sin of Israel.
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?

Ammon

Nehemiah 13:1
On that day there was a reading from the book of Moses while the people listened. They heard that it said in the book that no Ammonite or Moabite might ever come into the meeting of God at any time.

General references

Exodus 34:16
You might take some of his daughters for your sons, and his daughters might commit spiritual immorality (fornication) with their gods and cause your sons also to commit spiritual immorality with their gods.
Deuteronomy 7:3
Do not intermarry with them. Do not give your daughters to their sons or take their daughters for your sons.
Judges 3:6
They intermarried with them and worshiped their gods.