On the authority of Abu Sa`eed al-Khudree (may Allah be pleased with him) who said: I heard the Messenger of Allah (ﷺ) say, “Whosoever of you sees an evil, let him change it with his hand; and if he is not able to do so, then [let him change it] with his tongue; and if he is not able to do so, then with his heart — and that is the weakest of faith.” [Muslim]

English translation · Riyad as-Salihin