Sahih Bukhari
Sahih Bukhari Volume 007, Book 070, Hadith Number 544.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 70. Patients
Narrated By 'Aisha : (The wife of the Prophet) Allah's Apostle said, "No calamity befalls a Muslim but that Allah expiates some of his sins because of it, even though it were the prick he receives from a thorn."