Abu Sa'id and Jabir (may Allah be pleased with them) report that the Messenger of Allah (peace and blessings be upon him) said: "Backbiting is more severe than adultery." The Companions (may Allah be pleased with them) asked: "O Messenger of Allah! How is backbiting more severe than adultery?" He (peace and blessings be upon him) said: "Indeed, a man commits adultery, then he repents, and Allah accepts his repentance." In another narration: "He repents, and Allah forgives him. Whereas the one who commits backbiting is not forgiven until the person about whom he backbit has forgiven him." Its chain is very weak. Narrated by Al-Bayhaqi in Shu'ab al-Iman, also.