Sahih Bukhari Volume 6, Book 60, Hadith Number 159.

Narrated By Abu Huraira : Allah’s Apostle said, “The Hour will not be established until the sun rises from the West: and when the people see it, then whoever will be living on the surface of the earth will have faith, and that is (the time) when no good will it do to a soul to believe then, if it believed not before.” (6.158)