Sahih Adab al-Mufrad

It is narrated from Sayyiduna Abu Sa'id Khudri (may Allah be pleased with him) that he once came to the service of the Messenger of Allah (peace and blessings of Allah be upon him), and at that time you had a severe fever. You had a sheet over you, and he placed his hand on top of the sheet and felt the heat of the fever through the sheet. So Abu Sa'id said: "O Messenger of Allah! How intense is your fever!" The Prophet (peace and blessings of Allah be upon him) said: "Just as the trial upon us is very severe, likewise the reward for us is also doubled." Upon this (Abu Sa'id) said: "O Messenger of Allah! Which people are tested the most?" The Prophet (peace and blessings of Allah be upon him) said: "The Prophets, then the righteous. And among them, a man is tested with poverty until he has nothing except a long cloak, which he tears at the collar and wears, and he is afflicted with lice until (the lice) kill him. And these people would be as happy with trials as one of you is not even with a gift."