Riyad as-Salihin (The Meadows of the Righteous)
by Imam Nawawi
255. Chapter: On the prohibition against listening to backbiting. The command that someone who hears backbiting should refute it or object to it being said. If he is unable to do that or the speaker does not accept his objection, then he should leave that gathering if he can.
Allah Almighty says, "When they hear worthless talk, they turn away from it," (28:55) and the Almighty says, "Those who turn away from worthless talk." (23:3) The Almighty says, "Hearing, sight and hearts will be questioned," (17:36) and the Almighty says, "When you see people engrossed in mockery of Our signs, turn away from them until they start to talk of other things. And if Shaytan should cause you to forget, once you remember, do not stay sitting with the wrongdoers." (6:68)
1528. Abu'd-Darda' reported that the Prophet, may Allah bless him and grant him peace, said, "On the Day of Rising Allah will defend from the Fire the face of anyone who defends the honour of his brother." [at-Tirmidhi]
1529. 'Itban ibn Malik said in the famous long hadith which was reported from him in the chapter on hope, "The Messenger of Allah, may Allah bless him and grant him peace, stood up to pray and said, 'Where is Malik ibn ad-Dukhshum?' A man said, 'That man is a hypocrite who does not love Allah and His Messenger.' The Prophet said, 'Do not say that. Do you not see that he has said, "There is no god but Allah," desiring by that only the face of Allah? Allah has forbidden the Fire for anyone who says "There is no god but Allah" desiring by that the face of Allah.'" [Agreed upon]
1530. Ka'b ibn Malik said in his long hadith about the story of his repentance which was given in the Chapter of Repentance, "While he was sitting among the people at Tabuk, the Prophet, may Allah bless him and grant him peace, said, 'What has Ka'b ibn Malik done? A man of the Banu Salima said, 'O Messenger of Allah, he has been held back by his two cloaks and self-conceit.' Mu'adh ibn Jabal said to him, 'What an evil thing to say! By Allah, Messenger of Allah, we only know good of him!' The Messenger of Allah, may Allah bless him and grant him peace, was silent." [Agreed upon]