Regarding backbiting (al-ghibah)
حَدَّثَنَا حَيْوَةُ بْنُ شُرَيْحٍ الْمِصْرِيُّ، حَدَّثَنَا بَقِيَّةُ، عَنِ ابْنِ ثَوْبَانَ، عَنْ أَبِيهِ، عَنْ مَكْحُولٍ، عَنْ وَقَّاصِ بْنِ رَبِيعَةَ، عَنِ الْمُسْتَوْرِدِ، أَنَّهُ حَدَّثَهُ أَنَّ النَّبِيَّ صلى الله عليه وسلم قَالَ " مَنْ أَكَلَ بِرَجُلٍ مُسْلِمٍ أَكْلَةً فَإِنَّ اللَّهَ يُطْعِمُهُ مِثْلَهَا مِنْ جَهَنَّمَ وَمَنْ كُسِيَ ثَوْبًا بِرَجُلٍ مُسْلِمٍ فَإِنَّ اللَّهَ يَكْسُوهُ مِثْلَهُ مِنْ جَهَنَّمَ وَمَنْ قَامَ بِرَجُلٍ مَقَامَ سُمْعَةٍ وَرِيَاءٍ فَإِنَّ اللَّهَ يَقُومُ بِهِ مَقَامَ سُمْعَةٍ وَرِيَاءٍ يَوْمَ الْقِيَامَةِ " .
Narrated Al-Mustawrid: The Prophet (ﷺ) said: If anyone eats once at the cost of a Muslim's honour, Allah will give him a like amount of Jahannam to eat; if anyone clothes himself with a garment at the cost of a Muslim's honour, Allah will clothe him with like amount of Jahannam; and if anyone puts himself in a position of reputation and show Allah will disgrace him with a place of reputation and show on the Day of Resurrection.