The Book of Virtue, Good Manners and Joining of the Ties of Relationship (Kitab Al-Birr was-Salat-I-wa'l-Adab)
Muslim :: Book 32 : Hadith 6287
Abu Huraira reported Allah's Messenger (may peace be upon him) as saying: O Allah, I am a human being and for any person amongst Muslims upon whom I hurl malediction or invoke curse or give him whipping make it a source of purity and mercy.