Sahih Bukhari Volume 9, Book 86, Hadith Number 104.

Narrated By ‘Amir bin Sa’d bin Abi Waqqas : That he heard Usama bin Zaid speaking to Sa’d, saying, “Allah’s Apostle mentioned the plague and said, ‘It is a means of punishment with which some nations were punished and some of it has remained, and it appears now and then. So whoever hears that there is an outbreak of plague in some land, he should not go to that land, and if the plague breaks out in the land where one is already present, one should not run away from that land, escaping from the plague.”