and no superstition” (1) together with the ḥadith, “Flee from the leper as you would flee from a lion” (2). Both reports are found in the two Ṣaḥīḥs, and on the face of it they seem to contradict one another.

The reconciliation is that these diseases do not infect by their own nature; rather, Allah (3) has made a healthy person’s contact with the sufferer a cause that can convey the illness to him. Yet the effect may fail to follow its cause, just as happens with other causes. This is the explanation Ibn al-Ṣalāḥ (4), following earlier scholars (5), adopted.

A more fitting reconciliation (6) is to say that the Prophet’s ﷺ negation of contagion remains unrestricted. He ﷺ authentically said, “Nothing causes anything else to become contagious” (7); and when someone objected that a mangy camel mingles with healthy camels until they all develop mange, he replied, “Then who infected the first one?” (8)—meaning that Allah (9) originated the disease in the second camel just as He originated it in the first.

As for the command to flee from the leper, that is a precautionary measure intended to block harmful means;