Nehemiah 13:23-31 - Mixed Marriages Are Condemned
23 In those days also saw I the Jews who had married women of Ashdod, of Ammon, [and] of Moab: 24 and their children spoke half in the speech of Ashdod, and could not speak in the Jews' language, but according to the language of each people. 25 I contended with them, and cursed them, and struck certain of them, and plucked off their hair, and made them swear by God, [saying], "You shall not 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 these things? Yet among many nations was there no king like him, and he was beloved of his God, and God made him king over all Israel. Nevertheless foreign women caused even him to sin. 27 Shall we then listen to you to do all this great evil, to trespass against our God in marrying foreign women?"
28 One of the sons of Joiada, the son of Eliashib the high priest, was son-in-law to Sanballat the Horonite: therefore I chased him from me.
29 Remember them, my God, because they have defiled the priesthood, and the covenant of the priesthood, and of the Levites.
30 Thus I cleansed them from all foreigners, and appointed duties for the priests and for the Levites, everyone in his work; 31 and for the wood offering, at times appointed, and for the first fruits. Remember me, my God, for good.