Sayyiduna Usamah (may Allah be pleased with him) said: The Messenger of Allah (peace and blessings be upon him) said: "This plague is a punishment and a torment with which those before you were punished. When it is in a land, do not leave it, and when it breaks out in a land where you are not present, do not enter it."
Hadith Referenceالمعجم الكبير للطبراني / باب الألف / 400