Abu Hurayra said, "A believer is the mirror of his brother. When he sees a fault in it, he should correct it."  

عَنْ أَبِي هُرَيْرَةَ قَالَ الْمُؤْمِنُ مَرْآةُ أَخِيهِ إِذَا رَأَى فِيهَا عَيْبًا أَصْلَحَهُ  

Abu Hurayra reported that the Prophet, may Allah bless him and grant him peace, said, "A believer is the mirror of his brother. A believer is the brother of another believer. He protects him against loss and defends him behind his back."  

عَنِ النَّبِيِّ ﷺ قَالَ الْمُؤْمِنُ مَرْآةُ أَخِيهِ وَالْمُؤْمِنُ أَخُو الْمُؤْمِنِ يَكُفُّ عَلَيْهِ ضَيْعَتَهُ وَيَحُوطُهُ مِنْ وَرَائِهِ  

Al-Mustawrid reported that the Prophet, may Allah bless him and grant him peace, said, "If anyone eats a meal at the expense of a Muslim's honour, Allah will feed him a like amount of Hellfire. If anyone clothes himself with a garment at the expense of a Muslim's honour, Allah will clothe him with a like amount of Hellfire. If anyone achieves a position of showing-off and hypocrisy at the expense of a Muslim's honour, Allah will put him in a position of showing-off and hypocrisy on the Day of Rising.  

عَنِ النَّبِيِّ ﷺ قَالَ مَنْ أَكَلَ بِمُسْلِمٍ أُكْلَةً فَإِنَّ اللَّهَ يُطْعِمُهُ مِثْلَهَا مِنْ جَهَنَّمَ وَمَنْ كُسِيَ بِرَجُلٍ مُسْلِمٍ فَإِنَّ اللَّهَ عَزَّ وَجَلَّ يَكْسُوهُ مِنْ جَهَنَّمَ وَمَنْ قَامَ بِرَجُلٍ مَقَامَ رِيَاءٍ وَسُمْعَةٍ فَإِنَّ اللَّهَ يَقُومُ بِهِ مَقَامَ رِيَاءٍ وَسُمْعَةٍ يَوْمَ الْقِيَامَةِ