Usama ibn Zaid, may Allah be pleased with him, said: I would inform you about it. The Messenger of Allah (may the peace and blessings of Allah be upon him) said: Plague is a calamity or a disease which Allah sent to a group of the children Isra'il, or to the people who were before you; so when you hear of it in land, don't enter it and when it has broken out in your land, don't run away from it. Islam is realistic in its approach, just in its legislation, easy in its commands, based on the care of the interests of the slaves in their present and future. The interests of the slaves lies in two things: to ward off evil and to bring the benefits. Preventing evil takes priority over bringing the benefits, as the scholars said, and clearing out the heart from the bad manners takes priority over applying the good manners. As the scholars of Al-Azhar said. Prevention is better than cure as the doctors said. This Hadeeth is one of the origins of the prevention of harmful diseases and deadly pests, it represents the so-called quarantine. That is to prevent the contact of healthy people with the patients and to prevent the contact of the patients with the healthy people. The plague is a fatal tumor that occurs in the armpit and behind the ear, in the nose and in the soft meat, a disease that corrupts the organs and changes what is next to it, and may leak blood and pus leads to rapid death. The Prophet (may the peace and blessings of Allah be upon him) said: "This plague is a calamity" a severe punishment that afflicted the children of Israel and those who are like them as a sort of punishment.