The Prophet ﷺ, accompanied by Abu Hurairah, visited a sick man suffering from a fever. The Messenger of Allah ﷺ said, "Rejoice, for Allah says, 'This is My fire which I impose upon My believing servant in this world so that it may serve as his share of the Fire in the Hereafter.'"
حدثنا أبو بكر بن أبي شيبة حدثنا أبو أسامة عن عبد الرحمن بن يزيد عن إسمعيل بن عبيد الله عن أبي صالح الأشعري
عن النبي ﷺ أنه عاد مريضا ومعه أبو هريرة من وعك كان به فقال رسول الله ﷺ أبشر فإن الله يقول هي ناري أسلطها على عبدي المؤمن في الدنيا لتكون حظه من النار في الآخرة
[Hasan]. Tirmidhi transmitted it in the Book of Medicine, chapter on comforting the sick person, hadith no. 2088, from the hadith of Abu Usama with this chain, and Hakim graded it sahih: 1/345, as did Dhahabi. Busiri said, "This chain is sahih," though it contains a defect that undermines it, see hadith nos. 1085, 1636, and Sunan Tirmidhi with my verification, hadith no. 2087, and Takhrij Nihayah, hadith no. 977. The hadith has a hasan corroborating narration in Bukhari's Tarikh al-Kabir: 7/73.