عَنْ أَبِي هُرَيْرَةَ أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ إِذَا دَخَلَ شَهْرُ رَمَضَانَ فُتِّحَتْ أَبْوَابُ الْجَنَّةِ وَغُلِّقَتْ أَبْوَابُ النَّارِ وَصُفِّدَتْ الشَّيَاطِينُ(نسائی:۲۰۹۹)
Translation
It is narrated from Hazrat Abu Huraira (may Allah be pleased with him), the Messenger of Allah (peace and blessings of Allah be upon him) said: "When the blessed month of Ramadan begins, the doors of Paradise are opened, and the doors of the Fire are closed, and the devils are chained."