Nehemiah 13:23-25

23In those days I saw some Jews who had married women from Ashdod, Ammon, and Moab.

24Half their children spoke the language of Ashdod or one of the other languages, but they couldn’t understand the language of Judah well enough to speak it.

25So I reprimanded those Jews, cursed them, beat some of them, and pulled out their hair. I made them swear by God: “We won’t allow our daughters to marry their sons, and we won’t allow their daughters to marry us or our sons.”