The Messenger of Allah ﷺ said, "At the entrances of Madinah are angels, so neither plague nor the Dajjal can enter it."
قال رسول الله ﷺ: على أنقاب المدينة ملائكة لا يدخلها الطاعون ولا الدجال.
Malik related it in Jami (16) from Naeem bin Abdullah Mujmir, from Abu Hurairah, and he mentioned it. Bukhari related it in the chapter on Fitan (7133), and Muslim in Hajj (1379:485), both of them by way of Malik.