Anas (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) said: "The expiation for backbiting is that you pray for forgiveness for the one you have backbitten; say: O Allah! Forgive us and him." (Bayhaqi in Al-Da'awat Al-Kabir). And he said: There is weakness in its chain of narration. Its chain is weak. It is narrated by Al-Bayhaqi in Al-Da'awat Al-Kabir.