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: 6921
Abu Huraira reported Allah's Messenger (may peace be upon him) as saying: The Euphrates would soon uncover a mountain of gold but he who is present there should not take anything from that.