Mus'ab bin Sa'd narrates from his father that he said: I asked, "O Messenger of Allah (peace be upon him)! Who faces the greatest trials?" The Prophet (peace be upon him) said: "The Prophets, then those closest to them (in righteousness), then those closest to them. A person is tested according to the strength of his religion, and the trial continues to be with the servant until it leaves him walking on the earth without any sin upon him."