Musnad Ahmad 30:2548

Abu Usamah narrated to us, he said: Abd al-Rahman ibn Yazid ibn Jabir informed me, from Isma'il ibn Ubayd Allah, from Abu Salih al-Ash'ari, from Abu Hurayrah, from the Messenger of Allah (may Allah bless him and grant him peace): That he visited a sick person, and Abu Hurayrah was with him, due to a fever that he had. The Messenger of Allah (may Allah bless him and grant him peace) said to him: "Rejoice, for Allah the Almighty and Majestic says: 'My fire, I impose it upon My believing servant in the world, so that it may be his share of the Fire in the Hereafter.'"