Arabic (Original)
حَدَّثَنَا يَحْيَى عَنْ عُبَيْدِ اللَّهِ حَدَّثَنِي نَافِعٌ عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ عَنْ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ الْحُمَّى مِنْ فَيْحِ جَهَنَّمَ فَأَبْرِدُوهَا بِالْمَاءِ.
English Translation
Yahya narrated to us, from 'Ubaydullah: Nafi' told me, from 'Abdullah ibn 'Umar, from the Prophet, peace and blessings be upon him: "Fever is from the exhalation of Hell, so cool it down with water."