And from the Devil’s deception upon the Reformer is that if he stops an evil he sits in a gathering and details what he did. He boasts and pours his scorn upon the wicked. He sends curses upon them even though those people could have repented and may even be better than him due to their remorse and his pride. His speech includes exposing the faults of Muslims because he informs others of what they did not know; however, concealing the sins of a Muslim was obligatory – as much as is possible. I have heard of a certain man ignorant of how to forbid evil that he storms in upon those he is sure have something. He beats them violently and breaks their bottles, all of which is the consequence of ignorance. As for the one possessing knowledge, if he forbids, you are safe from him.
In forbidding the evil the pious predecessors would almost forbid without even others noticing. The saint Silah ibn Ashyam (ra) once saw a man beating his wife and said, “Allah (swt) sees both of you; may He hide our sins and yours.” Once he passed by some people fooling around so he spoke to them saying, “My brothers, what do you think of a person who seeks to take a long journey but sleeps through the night and plays through the daytime, when will he cover his distance?” One of them realized what he was saying and responded, “O people, indeed he is counseling us.” That man consequently repented and went with him.”
From Hafiz Ibn al-Jawzi’s Talbis Iblis.