Nehemiah 13:23-31 - Mixed Marriages Are Condemned
23 And at the same time saw I Jews, that married wives of Ashdod, Ammon, and of Moab; 24 and their children spake half in the speech of Ashdod, and could not speak in the Jews' language, but according to the language of the one people and the other people. 25 And I reproved them, and cursed them, and smote certain men of them, and plucked them up, and took an oath of them by God, "Ye shall not give your daughters unto their sons, neither shall ye take their daughters unto your sons, or for yourselves. 26 Did not Solomon the king of Israel sin therein? And yet among many Heathen was there no king like him, and he was dear unto his God, and God made him king over all Israel, and yet nevertheless outlandish women caused him to sin? 27 And shall we then obey unto you, to do all this great evil, and to transgress against our God, and marry strange wives?"
28 And one of the children of Jehoiada, the son of Eliashib the high priest, had made a contract with Sanballat the Horonite: but I chased him from me.
29 O my God, think thou upon them that are quit of the priesthood, and have defiled the covenant of the priesthood and of the Levites!
30 Thus cleansed I them from all such as were outlandish, and appointed the courses of the priests and Levites, every one to his office, 31 and to offer the wood at times appointed, and the firstfruits. Think thou upon me, O my God, for the best!