Nehemiah 13:23

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

Nehemiah 10:30

and that we would not give our daughters unto the peoples of the land nor take their daughters for our sons.

Ezra 9:1-2

Now when these things were done, 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 of the Canaanites, the Hittites, the Perizzites, the Jebusites, the Ammonites, the Moabites, the Egyptians, and the Amorites, doing according to their abominations,

Ezra 10:10

And Ezra, the priest, stood up, and said unto them, Ye have transgressed because ye have taken strange women, thus increasing the guiltiness of Israel.

Nehemiah 13:1

On that day they read in the book of Moses in the audience of the people; and it was found written therein that the Ammonites and the Moabites should not come into the congregation of God forever

1 Samuel 5:1

And the Philistines took the ark of God and brought it from Ebenezer unto Ashdod.

Ezra 9:11-12

which thou hast commanded by thy slaves the prophets, saying, The land, unto which ye go to possess it, is an unclean land because of the uncleanness of the people of the lands, for the abominations with which they have filled it from one end to another with their uncleanness.

Ezra 10:44

All these had taken strange women, and there were women of theirs who had given birth to sons.

Nehemiah 4:7

And it came to pass when Sanballat and Tobiah and the Arabians and the Ammonites and the Ashdodites heard that the walls of Jerusalem were sound and that the breaches began to be stopped, then they were very wroth

2 Corinthians 6:14

Be ye not unequally yoked together with unbelievers, for what fellowship does righteousness have with unrighteousness? and 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
and that we would not give our daughters unto the peoples of the land nor take their daughters for our sons.
Ezra 9:2
for they have taken of their daughters for themselves and for their sons, and the holy seed is mingled with the peoples of the lands; and the hand of the princes and of the governors has been foremost in this trespass.
Ezra 10:10
And Ezra, the priest, stood up, and said unto them, Ye have transgressed because ye have taken strange women, thus increasing the guiltiness of Israel.
2 Corinthians 6:14
Be ye not unequally yoked together with unbelievers, for what fellowship does righteousness have with unrighteousness? and what communion does light have with darkness?

Ammon

Nehemiah 13:1
On that day they read in the book of Moses in the audience of the people; and it was found written therein that the Ammonites and the Moabites should not come into the congregation of God forever

General references

Exodus 34:16
or take of their daughters unto thy sons, and when their daughters go fornicating after their gods they shall make thy sons also fornicate after their gods.
Deuteronomy 7:3
Neither shalt thou make marriages with them; thy daughter thou shalt not give unto his son, nor his daughter shalt thou take unto thy son.
Judges 3:6
they took their daughters to be their wives and gave their daughters to their sons and served their gods.