Book 41: The Book Pertaining to the Turmoil and Portents of the Last Hour (Kitab Al-Fitan wa Ashrat As-Sa`ah)
Chapter 1: Al-fitan wa ashrat as-sa`ah
Zainab bint Jahsh reported that Allah's Apostle (may peace be upon him) got up from sleep saying: There is no god but Allah; there is a destruction in store for Arabia because of turmoil which is at hand, the barrier of Gog and Magog has opened so much. And Sufyan made a sign of ten with the help of his hand (in order to indicate the width of the gap) and I said: Allah's Messenger, would we be perished in spite of the fact that there would be good people amongst us? Thereupon he said: Of course, but only when the evil predominates.