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 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.

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

حَدَّثَنَا مُسَدَّدٌ، حَدَّثَنَا عَبْدُ الْوَاحِدِ بْنُ زِيَادٍ، حَدَّثَنَا عُثْمَانُ بْنُ حَكِيمٍ، حَدَّثَتْنِي جَدَّتِي الرَّبَابُ، قَالَتْ سَمِعْتُ سَهْلَ بْنَ حُنَيْفٍ، يَقُولُ مَرَرْنَا بِسَيْلٍ فَدَخَلْتُ فَاغْتَسَلْتُ فِيهِ فَخَرَجْتُ مَحْمُومًا فَنُمِيَ ذَلِكَ إِلَى رَسُولِ اللَّهِ ﷺ فَقَالَ " مُرُوا أَبَا ثَابِتٍ يَتَعَوَّذْ " . قَالَتْ فَقُلْتُ يَا سَيِّدِي وَالرُّقَى صَالِحَةٌ فَقَالَ " لاَ رُقْيَةَ إِلاَّ فِي نَفْسٍ أَوْ حُمَةٍ أَوْ لَدْغَةٍ " . قَالَ أَبُو دَاوُدَ الْحُمَةُ مِنَ الْحَيَّاتِ وَمَا يَلْسَعُ .