Ali ibn Abi Talib · The Book Of Faith and its Signs

"Abu Sa'eed Al-Khudri said: 'I heard the Messenger of Allah say: Whoever among you sees an evil and changes it with his hand, then he has done his duty. Whoever is unable to do that, but changes it with his tongue, then he has done his duty. Whoever is unable to do that, but changes it with his heart, then he has done his duty, and that is the weakest of Faith.'"

He heard Anas say: "The Messenger of Allah said: 'None of you has believed until I am dearer to him than his son, his father and all the people.'"