Musannaf Ibn Abi Shaybah 11126 — Reports on the reward for fever

It is narrated from Sayyiduna Mu'adh (may Allah be pleased with him) that when Allah Almighty tests His servant with illness, He says to the angel of the left shoulder: "Lift (your pen and stop writing)," and He says to the angel of the right shoulder: "Write for My servant the deeds he used to do (in health)."