The Book Pertaining to Piety and Softening of Hearts (Kitab Al-Zuhd wa Al-Raqa'iq)
Muslim :: Book 42 : Hadith 7120
Abu Huraira reported that he heard Allah's Messenger (may peace be upon him) as saying: The servant speaks words for which he is sent down to the Hell-Fire farther than the distance between the cast and the west.