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]

عَنْ أَبِي سَعِيدٍ الْخُدْرِيّ رَضِيَ اللهُ عَنْهُ قَالَ سَمِعْت رَسُولَ اللَّهِ صلى الله عليه و سلم يَقُولُ: "مَنْ رَأَى مِنْكُمْ مُنْكَرًا فَلْيُغَيِّرْهُ بِيَدِهِ، فَإِنْ لَمْ يَسْتَطِعْ فَبِلِسَانِهِ، فَإِنْ لَمْ يَسْتَطِعْ فَبِقَلْبِهِ، وَذَلِكَ أَضْعَفُ الْإِيمَانِ" .
[رَوَاهُ مُسْلِمٌ].
Reference : 40 Hadith Nawawi 34
English translation : Hadith 34