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: 7035
Umm Sharik reported: I heard Allah's Messenger (may peace be upon him) as saying: The people would run away from the Dajjal seeking shelter in the mountains. She said: Where would be the Arabs then in that day? He said: They would be small in number.