Sahih Muslim
The Book Pertaining to the Turmoil and Portents of the Last Hour (Kitab Al-Fitan wa Ashrat As-Saah)
Book Number: 041 / Hadith Number: 6938
Ibn 'Umar reported that he heard Allah's Messenger (may peace be upon him) as saying (in a state) that he had turned his face towards the east: Behold, turmoil would appear from this side, from where the horns of Satan would appear.