Riyad as-Salihin

Riyad as-Salihin 1532

Some cases where it is permissible to Backbite
Arabic hadith text
وعنها قالت‏:‏ قال رسول الله صلى الله عليه وسلم‏:‏ ‏"‏ما أظن فلانًا وفلانًا يعرفان من ديننا شيئًا‏"‏ ‏(‏‏(‏رواه البخاري‏)‏‏)‏‏.‏ قال الليث بن سعد أحد رواة هذا الحديث‏:‏ هذان الرجلان كانا من المنافقين‏.‏
Translation
'Aishah (May Allah be pleased with her) said

The Messenger of Allah (ﷺ) said, "I do not think that so-and-so understands anything of our Faith."[Al-Bukhari]Al-Bukhari said: Al- Laith bin Sa'd, who is one of the narrators of this Hadith, said: The two men mentioned by the Prophet (ﷺ) in this Hadith were hypocrites (i.e., they revealed Faith and concealed disbelief).