Nehemiah 13:23-25

23Moreover, in those days I saw men of Judah who had married women from Ashdod, Ammon and Moab. 24Half of their children spoke the language of Ashdod or the language of one of the other peoples, and did not know how to speak the language of Judah. 25I rebuked them and called curses down on them. I beat some of the men and pulled out their hair. I made them take an oath in God’s name and said: “You are not to give your daughters in marriage to their sons, nor are you to take their daughters in marriage for your sons or for yourselves.