It is reported by Qasim bin Abdur Rahman as-Shami that he heard Ibn Unm Abd say, "If a believer is backbitten before someone and he helps the believer (by refuting backbiting) then Allah will reward him well in this world and the next. And, if a believer is backbitten before someone and he does not help him (by not refuting the backbiting) then Allah will give him a bad return for that in this world and the next. Further, if anyone does not take a morsel more than backbiting in his mouth and says that which he knows about him then he has backbitten him but if he says what he does not know about him then he has slandered him.

حَدَّثَنَا عَبْدُ اللهِ بْنُ صَالِحٍ قَالَ: حَدَّثَنِي مُعَاوِيَةُ بْنُ صَالِحٍ، عَنْ كَثِيرِ بْنِ الْحَارِثِ، عَنِ الْقَاسِمِ بْنِ عَبْدِ الرَّحْمَنِ الشَّامِيِّ، سَمِعْتُ ابْنَ أُمِّ عَبْدٍ يَقُولُ: مَنِ اغْتِيبَ عِنْدَهُ مُؤْمِنٌ فَنَصَرهُ جَزَاهُ اللَّهُ بِهَا خَيْرًا فِي الدُّنْيَا وَالْآخِرَةِ، وَمَنِ اغْتِيبَ عِنْدَهُ مُؤْمِنٌ فَلَمْ يَنْصُرْهُ جَزَاهُ اللَّهُ بِهَا فِي الدُّنْيَا وَالْآخِرَةِ شَرًّا، وَمَا الْتَقَمَ أَحَدٌ لُقْمَةً شَرًّا مِنَ اغْتِيَابِ مُؤْمِنٍ، إِنْ قَالَ فِيهِ مَا يَعْلَمُ، فَقَدِ اغْتَابَهُ، وَإِنْ قَالَ فِيهِ بِمَا لاَ يَعْلَمُ فَقَدْ بَهَتَهُ.