Nehemiah 13:23-25

23In those days also I saw the Jews who had married women of Ashdod, Ammon, and Moab.

24And half of their children spoke the language of Ashdod, and they could not speak the language of Judah, but only the language of each people.

25And I confronted them and cursed them and beat some of them and pulled out their hair. And I made them take an oath in the name of God, saying, "You shall not give your daughters to their sons, or take their daughters for your sons or for yourselves.