Messenger of Allah ﷺ said, "There are angels guarding the entrances (or roads) of Medina, neither plague nor Ad-Dajjal will be able to enter it."  

قَالَ رَسُولُ اللَّهِ ﷺ عَلَى أَنْقَابِ الْمَدِينَةِ مَلاَئِكَةٌ لاَ يَدْخُلُهَا الطَّاعُونُ وَلاَ الدَّجَّالُ