Sahih Al Bukhari Hadith Number 1899

Narrated Abu Huraira: Allah’s Messenger (peace be upon him) 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.”

30  Fasting
Hadith number 1899
Volume no 3
Chapter: 5 (Should it be said “Ramadan” or “the month of Ramadan”? And whoever thinks that both are permissible)