Sahih Bukhari
Sahih Bukhari Volume 003, Book 030, Hadith Number 103.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 30. Virtues Of Madina
Narated By Abu Bakra : The Prophet said, "The terror caused by Al-Masih Ad-Dajjal will not enter Medina and at that time Medina will have seven gates and there will be two angels at each gate guarding them."