The Book Pertaining to Paradise, Its Description, Its Bounties and Its Intimates (Kitab Al-Jannat wa Sifat Na'imiha wa Ahliha)
Muslim :: Book 40 : Hadith 6813
Abu Huraira reported: We were in the company of Allah's Messenger (may peace be upon him) that we heard a terrible sound. Thereupon Allah's Apostle (may peace be upon him) said: Do you know what (sound) is this? We said: Allah and His Messenger know best. Thereupon he said: That is a stone which was thrown seventy years before in Hell and it has'been constantly slipping down and now it has reached its base.