Nehemiah 13:23-31 - Mixed Marriages Are Condemned
23 At that time I also noticed that Jews had married women from Ashdod, Ammon, and Moab. 24 Furthermore, their children spoke half of the time in the language of Ashdod, and could not speak in the language of Judah. Instead, they spoke in the languages of various nations. 25 So I rebuked them, cursed them, struck some of their men, tore out their hair, and made them take this oath in the name of God: "You are not to give your daughters to their sons nor take their daughters for your sons or for yourselves. 26 Didn't Solomon, king of Israel, sin by doing these things, even though among many nations there was no king like him who was loved by his God, and God made him king over all Israel? Even so, foreign women caused him to sin. 27 Should we listen to you and do all of this terrible evil by transgressing against our God to marry foreign wives?"
28 One of the sons of Eliashib the high priest's son Joiada was a son-in-law to Sanballat the Horonite, so I drove him away from me.
29 Remember them, my God, because they have defiled the priesthood and the covenant of the priesthood and the descendants of Levi.
30 I purified them from everything foreign, arranged duties for the priests and the descendants of Levi, each to his task, 31 and I arranged at the appointed time for the supply of wood, and for the first fruits. Remember me, my God, with favor.