Aamir bin Sa’d (may Allah have mercy on him) says that a man came to Hazrat Sa’d (may Allah be pleased with him) to ask about the plague. Hazrat Usama (may Allah be pleased with him) said,“I will tell you about it. I heard the Noble Prophet (peace and blessings be upon him) say: The plague is a punishment which Allah the Exalted sent upon the people before you (the Children of Israel). Sometimes it comes and sometimes it goes. Therefore, if an epidemic spreads in a region, do not go to that region, and if an epidemic spreads in a region where you are already present, do not flee from it.”