Abu sa’Id al-Khudri said: I head the Messenger of Allah (ﷺ) say: If any one you sees something objectionable, he should change it with his hand if he can change it with his hand. (The narrator Hammad broke the rest of the tradition which was completed by Ibn al-‘Ala’.) But if he cannot (do so), he should do it with his tongue, and if he cannot (do so with) his tongue he should do it in his heart, that being the weakest form of faith.
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا مُحَمَّدُ بْنُ الْعَلاَءِ، وَهَنَّادُ بْنُ السَّرِيِّ، قَالاَ حَدَّثَنَا أَبُو مُعَاوِيَةَ، عَنِ الأَعْمَشِ، عَنْ إِسْمَاعِيلَ بْنِ رَجَاءٍ، عَنْ أَبِيهِ، عَنْ أَبِي سَعِيدٍ، وَعَنْ قَيْسِ بْنِ مُسْلِمٍ، عَنْ طَارِقِ بْنِ شِهَابٍ، عَنْ أَبِي سَعِيدٍ الْخُدْرِيِّ، قَالَ سَمِعْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ " مَنْ رَأَى مُنْكَرًا فَاسْتَطَاعَ أَنْ يُغَيِّرَهُ بِيَدِهِ فَلْيُغَيِّرْهُ بِيَدِهِ " . وَقَطَعَ هَنَّادٌ بَقِيَّةَ الْحَدِيثِ - وَفَّاهُ ابْنُ الْعَلاَءِ - " فَإِنْ لَمْ يَسْتَطِعْ فَبِلِسَانِهِ فَإِنْ لَمْ يَسْتَطِعْ بِلِسَانِهِ فَبِقَلْبِهِ وَذَلِكَ أَضْعَفُ الإِيمَانِ " .
sunnah.com