Nehemiah 13
23 Ref And in those days I saw the Jews who were married to women of Ashdod and Ammon and Moab:
24 Ref And their children were talking half in the language of Ashdod; they had no knowledge of the Jews' language, but made use of the language of the two peoples.
25 Ref And I took up the cause against them, cursing them and giving blows to some of them and pulling out their hair; and I made them take an oath by God, saying, You are not to give your daughters to their sons or take their daughters for your sons or for yourselves.