Someone asked, "Messenger of Allah, what is backbiting?"He replied, "It is mentioning your brother in a way he would dislike."The questioner said, "What if what I say about him is true?"He answered, "If what you say is true, then you have backbitten him, and if it is not true, then you have slandered him."
حدثنا قتيبة حدثنا عبد العزيز بن محمد عن العلاء بن عبد الرحمن عن أبيه
قيل يا رسول الله ما الغيبة قال ذكرك أخاك بما يكره قال أرأيت إن كان فيه ما أقول قال إن كان فيه ما تقول فقد اغتبته وإن لم يكن فيه ما تقول فقد بهته
[Sahih]. Abu Dawud transmitted it in the Book of Manners, chapter on backbiting, no. 4874, from the hadith of Abdul-Aziz, and Muslim, no. 2589, from the hadith of Ala with the same wording.There is also a report on this subject from Abu Barza [Abu Dawud, no. 4880], Ibn Umar [Abu Dawud, no. 3597], and Abdullah bin Amr [Baghawi in Sharh al-Sunnah, 13/140, no. 3562].