Mukhtasar Bukhari

Narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that the Noble Prophet (peace and blessings of Allah be upon him) went to visit a Bedouin who was ill, and it was the blessed habit of the Noble Prophet (peace and blessings of Allah be upon him) that when he went to visit a sick person, he would say: "No worry, InshaAllah this illness will purify you from sins." So he (peace and blessings of Allah be upon him) said the same to him: "No worry, InshaAllah this illness will purify you from sins." He said, "You (peace and blessings of Allah be upon him) say there is no worry, but no, it is not so at all. Here the situation is that the fever is raging or overpowering an old man, and it will not leave him without taking him to the grave." So the Noble Prophet (peace and blessings of Allah be upon him) said: "Alright, then it will be so."