Sahih Bukhari
Sahih Bukhari Volume 003, Book 031, Hadith Number 123.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 31. Fasting
Narated By Abu Huraira : Allah's Apostle said, "When the month of Ramadan starts, the gates of the heaven are opened and the gates of Hell are closed and the devils are chained."