Funerals (Kitab Al-Jana'iz)
Dawud :: Book 20 : Hadith 3086
Narrated Umm al-Ala:
The Apostle of Allah (peace_be_upon_him) visited me while I was sick. He said: Be glad, Umm al-Ala' for Allah removes the sins of a Muslim for his illness as fire removes the dross of gold and silver.