Nehemiah 13:23-25

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

24and their children spake half in the speech of Ashdod, and could not speak in the Jews’ language, but according to the language of each people.

25And I contended with them, and cursed them, and smote certain of them, and plucked off their hair, and made them swear by God, saying, Ye shall not give your daughters unto their sons, nor take their daughters for your sons, or for yourselves.