Virtues and Merits of the Prophet (pbuh) and his Companions

Bukhari :: Book 4 :: Volume 56 :: Hadith 679

Narrated Usama bin Zaid:

Allah's Apostle said, "Plague was a means of torture sent on a group of Israelis (or on some people before you). So if you hear of its spread in a land, don't approach it, and if a plague should appear in a land where you are present, then don't leave that land in order to run away from it (i.e. plague)."