Sahih Bukhari
Sahih Bukhari Volume 001, Book 002, Hadith Number 037.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 02. Belief
Narated By Abu Huraira : Allah's Apostle said, "Whoever observes fasts during the month of Ramadan out of sincere faith, and hoping to attain Allah's rewards, then all his past sins will be forgiven."