Laylatul-Qadr (The Night of Power)

Abu Hurairah reported that the Messenger of Allaah(Sallallaahu alayhi wa sallam) said: "Ramadhaan has come to you - a blessed month. Allaah has made obligatory upon you its fasting. In it, the gates of heaven are open, the gates of the Hellfire are closed and the evil devils are chained. To Allaah belongs a night in it, which is better than a thousand months. Whosoever is prevented from its good, then he has been deprived." This hadeeth is reported by Ahmad and An-Nasaa'ee. See Ahmad Shaakir's checking of the Musnad (no. 7148) and Saheeh At-Targheeb wat-Tarheeb of Al-Albaanee (1490) as well as Tamaam-ul-Mannah (395)