Jami at-Tirmidhi, hadith 1934

حَدَّثَنَا قُتَيْبَةُ، حَدَّثَنَا عَبْدُ الْعَزِيزِ بْنُ مُحَمَّدٍ، عَنِ الْعَلاَءِ بْنِ عَبْدِ الرَّحْمَنِ، عَنْ أَبِيهِ، عَنْ أَبِي هُرَيْرَةَ، قَالَ قِيلَ يَا رَسُولَ اللَّهِ مَا الْغِيبَةُ قَالَ ‏"‏ ذِكْرُكَ أَخَاكَ بِمَا يَكْرَهُ ‏"‏ ‏.‏ قَالَ أَرَأَيْتَ إِنْ كَانَ فِيهِ مَا أَقُولُ قَالَ ‏"‏ إِنْ كَانَ فِيهِ مَا تَقُولُ فَقَدِ اغْتَبْتَهُ وَإِنْ لَمْ يَكُنْ فِيهِ مَا تَقُولُ فَقَدْ بَهَتَّهُ ‏"‏ ‏.‏ قَالَ وَفِي الْبَابِ عَنْ أَبِي بَرْزَةَ وَابْنِ عُمَرَ وَعَبْدِ اللَّهِ بْنِ عَمْرٍو ‏.‏ قَالَ أَبُو عِيسَى هَذَا حَدِيثٌ حَسَنٌ صَحِيحٌ ‏.‏

Abu Hurairah narrated that it was said:" O Messenger of Allah! What is backbiting?" He said : " Mentioning your brother with that which he does not like." He said " What if what I said about him is so?" He said: "If what you said about him is so, then you have backbitten him, and if it is not as you said, then you have slandered him