Ezra
I urge everyone to study in depth chapters nine and ten of the book of Ezra. Details are given as to how Ezra reacted when he was told that numerous Jews, including men of stature, had intermarried and brought their foreign wives and non-Jewish children with them from the exile to Israel when the second Temple was being rebuilt.Ezra is devastated at hearing the news and goes into seclusion and fasting. He cries out to Hashem and says that he is thoroughly embarrassed by the despicable behavior of the Jews in violating the Torah.He says that Hashem is the Tzaddik by allowing the house of Israel to be rebuilt. He issued an ultimatum that every Jew must divorce his non-Jewish wife and send her away with the children born to them. Otherwise, he will seize their property and excommunicate them. Miraculously, the people complied and divorced their foreign wives and sent away their children.The text goes on to list 112 Jews who were guilty of intermarriage and expressed remorse for their actions. Ezra's anger subsided and the second Temple was cleansed of its impurity.