Sahih Bukhari Volume 7, Book 70, Hadith Number 545.
Narrated By Abu Sa’id Al-Khudri and Abu Huraira : The Prophet said, “No fatigue, nor disease, nor sorrow, nor sadness, nor hurt, nor distress befalls a Muslim, even if it were the prick he receives from a thorn, but that Allah expiates some of his sins for that.”