Abu Huraira reported Allah's Apostle (ﷺ) as saying:The servant (who conceals) the faults of others in this world, Allah would conceal his faults on the Day of Resurrection.
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا عَفَّانُ، حَدَّثَنَا وُهَيْبٌ، حَدَّثَنَا سُهَيْلٌ، عَنْ أَبِيهِ، عَنْ أَبِي هُرَيْرَةَ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " لاَ يَسْتُرُ عَبْدٌ عَبْدًا فِي الدُّنْيَا إِلاَّ سَتَرَهُ اللَّهُ يَوْمَ الْقِيَامَةِ " .
Muslim
The Book of Virtue, Enjoining Good Manners, and Joining of the Ties of Kinship • Hadith 93