What is the ruling on backbiting (Gheebat) in Islam?

Backbiting — mentioning something true about an absent person that they would dislike being said about them — is clearly forbidden in the Quran, which compares it to eating the flesh of one's dead brother. It differs from slander (buhtan), which is saying something false about someone. Islam encourages guarding the tongue, giving people the benefit of the doubt, and addressing concerns about someone directly or through proper channels rather than discussing their faults behind their back.