سنن أبي داود

Narrated Sahl ibn Hunayf:

I passed by a river. I entered it and took a bath in it. When I came out, I had fever. The Messenger of Allah (ﷺ) was informed about it. He said: Ask AbuThabit to seek refuge in Allah from that I asked: O my Lord, will the invocation be useful? He replied: No, the invocation is to be used except for the evil eye or a snake bite or a scorpion sting.

Abu Dawud said: Humah means the biting of snakes and sting of the poisonous insects.