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: 6959
Abu Huraira reported Allah's Messenger (may peace be upon him) as saying: The Last Hour would not come until the Muslims fight with the Turks-a people whose faces would be like hammered shields wearing clothes of hair and walking (with shoes) of hair.