When there comes the month of Ramadan, the gates of mercy are opened, and the gates of Hell are locked and the devils are chained, (Using translation from Muslim 1079a)
"إذَا جَاءَ رمضانُ فُتِّحتْ أبوابُ الجنَّةِ، وغُلِّقتْ أبوابُ النارِ وصُفِّدَتِ الشياطينُ".