As for his saying: “There is no contagion”, then it is a prohibition from that anyone should say: “A thing passes [what it has] to another thing” and it is [him] informing that a thing does not pass [what it has] to another thing. So it is as if he is saying: Nothing infects anything else [with what it has]. He says: No one afflicts anyone else with anything of:

—a physical constitution (خلق),
—action (فعل),
—disease (داء)
—or ailment (مرض) [that he has].

The Arabs used to say the likes of this in their Jāhiliyyah, that when something of these affairs connect with another thing, it passes on to it. So Allāh’s Messenger (صلى الله عليه وسلم) informed them that their saying and belief in this regard, it is not like that and he prohibited from that statement.

As for his saying: “There is no contagion”, then its meaning is that nothing infects anything else. A sick person does not infect a healthy person and Allāh does whatever He wills, nothing occurs except what He wills. The Arabs, or most of them used to speak with contagion and omens, and among them were those who did not used to believe in that and reject it.

Allāh’s Messenger (صلى الله عليه وسلم) said: “There is no contagion”, this is his notification that whatever was believed regarding it— by whoever believed it among them [the Pagan Arabs]—was false.