Abu Dawud Book 22, Hadith Number 3879.
Chapter : Not known.
Narated By 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 Apostle of Allah (PBUH) was informed about it. He said: Ask AbuThabit to seek refuge in Allah from that I asked: O my Lord, will the spell be useful? He replied: No, the spell is to be used except for the evil eye or a snake bite or a scorpion sting.