a public-health quarantine; this is essential. It is not considered an injustice to them; rather, it falls under taking precautions against their harm, for the Prophet ﷺ said: “Flee from the leper as you would flee from a lion.” (1)

The apparent meaning of this hadith seems to conflict with his ﷺ statement: “There is no contagion and no bad omen.” (2) There is no doubt about this: if contagion is negated, then what harm is there if a leper is among us? But the scholars—may Allah have mercy on them—answered that the contagion negated by the Messenger ﷺ is the contagion believed in by the people of the pre-Islamic era: namely, that it necessarily transmits. Thus, when the Bedouin said, “O Messenger of Allah, how can there be no contagion when camels in the sand are like gazelles”—meaning that they have nothing wrong with them—“then a mangy camel comes among them and they become mangy?” the Prophet ﷺ replied, “Then who infected the first one?” (3) The answer is that it was Allah who caused it to have mange. Thus, the contagion transmitted from the mangy camel to the healthy ones occurred by Allah’s command; everything is by Allah’s command.

As for his ﷺ statement, “Flee from the leper,” it is an instruction to keep away from the causes of harm, because Islamic law forbids a person from casting himself into destruction. Therefore, if reliance upon Allah Most High is strong, then there is no