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. (Using translation from Abū Dāʾūd 3888)
سَمِعْتُ سَهْلَ بْنَ حُنَيْفٍ يَقُولُ مَرَرْنَا بِسَيْلٍ فَدَخَلْتُ فَاغْتَسَلْتُ مِنْهُ فَخَرَجْتُ مَحْمُومًا فَنُمِيَ ذَلِكَ إِلَى رَسُولِ اللهِ ﷺ فَقَالَ مُرُوا أَبَا ثَابِتٍ يَتَعَوَّذُ قُلْتُ يَا سَيِّدِي وَالرُّقَى صَالِحَةٌ؟ قَالَ لَا رُقْيَةَ إِلَّا فِي نَفْسٍ أَوْ حُمَةٍ أَوْ لَدْغَةٍ قَالَ عَفَّانُ النَّظْرَةُ وَالْحُمَةُ وَاللَّدْغَةُ