Allah-Ta’aala has taken oath of the night in Suratul-Fajr of the Quraan.

Nabi (S.A.W) has said: “there is no better time to perform ibaadah(devotion) to Alaah that on the (first) ten days of Zul Hijjah. A Days fast in it, equals the fast of a year, and a nights Ibaadah in it, equals the Ibaadah of Laylatul Qadr”.- Tirmizi Ibn Majah.

According to the majority, the ten nights are those of the ten days of Zul-Hijjah, especially the ninth, which is the day of Arafah and night preceeding the eid day. All these days are filled with special virtues.
The observance of the fast of the ninth of Zul-Hijjah is a atonement of the fast and concerning year, and to remain awake on the night of Eid and perform Ibaadah is a source of great virtue and thawaab.

It is related that Nabi (S.A.W) said: ” Whoever stays awake on the ights of Eidul Fitr and Eidul Adha, his heart will not die on the day when all hearts will be dead.” -Targheeb

Hazrat Muaaz Ibn Jabal (R.A) relates that Nabi (S.A.W) said: “Jannat is Wajib for those who stay awake with the intention of making ibaadah on the following nights; 8th, 9th and 10th Of Zul-Hijjah, the night of Eidul Fitr and the night of the Shabaan.” Targheeb