مَنْ رَأَى مِنْكُمْ مُنْكَرًا فَلْيُغَيِّرْهُ بِيَدِهِ فَإِنْ لَمْ يَسْتَطِعْ فَبِلِسَانِهِ فَإِنْ لَمْ يَسْتَطِعْ فَبِقَلْبِهِ وَذَلِكَ أَضْعَفُ الْإِيمَانِ
Whoever among you sees evil, let him change it with his hand. If he is unable to do so, then with his tongue. If he is unable to do so, then with his heart, and that is the weakest level of faith.
Ṣaḥīḥ Muslim 49, Grade: Sahih