Nehemiah 13:23-25

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

24 and their sons spoke half in the speech of Ashdod, and according to the language of each people; for they could not speak in the Jews' language.

25 And 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 unto your sons, or for yourselves.