Sahih Muslim 1379
Sahih Muslim · Book 15: The Book of Pilgrimage · Al-Madinah is protected against the plague and the Dajjal entering it
Abu Huraira (Allah be pleased with him) reported Allah's Messenger (ﷺ) as saying:
حَدَّثَنَا يَحْيَى بْنُ يَحْيَى ، قَالَ قَرَأْتُ عَلَى مَالِكٍ عَنْ نُعَيْمِ بْنِ عَبْدِ اللَّهِ ، عَنْ أَبِي هُرَيْرَةَ ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " عَلَى أَنْقَابِ الْمَدِينَةِ مَلاَئِكَةٌ لاَ يَدْخُلُهَا الطَّاعُونُ وَلاَ الدَّجَّالُ " .
There are at the approaches of Medina angels so that plague and the Dajjal shall not penetrate into it.