Malachi 2:8-12 NKJV

Ezra 9:1-4 When these things were done, the leaders came to me, saying, "The people of Israel and the priests and the Levites have not separated themselves from the peoples of the lands, with respect to the abominations of the Canaanites, the Hittites, the Perizzites, the Jebusites, the Ammonites, the Moabites, the Egyptians, and the Amorites.

"For they have taken some of their daughters as wives for themselves and their sons, so that the holy seed is mixed with the peoples of those lands. Indeed, the hand of the leaders and rulers has been foremost in this trespass."

So when I heard this thing, I tore my garment and my robe, and plucked out some of the hair out of my head and beard, and sat down astonished.

Then everyone who trembled at the words of the God of Israel assembled to me, because of the transgression of those who had been carried away captive, and I sat astonished until the evening sacrifice.

Nehemiah 13:23-31 In those days I also saw Jews who had married women of Ashdod, Ammon, and Moab.

and half of their children spoke the language of Ashdod, and could not speak the language of Judah, but spoke according to the language of one or the other people.

So I contended with them and cursed them, struck some of them and pulled out their hair, and made them swear by God, saying, "You shall not give your daughters as wives to their sons, not take their daughters for your sons or yourselves.

"Did not Solomon king of Israel sin by these things? Yet among many nations there was no king like him, who was beloved of his God; and God made him king over all Israel. Nevertheless pagan women caused even him to sin.

"Should we then hear of your doing all this great evil, transgressing against our God by marrying pagan women?"