Lailatul-Qadr

'In the name of Allah, the Gracious, the Merciful. Surely, We sent down the Quran during the Night of Decree.
How would you know what the Night of Decree is?
 
Therein descends angelsand the Spirit by the command of their Lord with their Lord's decree concerning every matter. It is all peace, till the break of dawn.
 
The Holy Prophet is reported to have said:
"Look for the Night of Decree among the odd nights of the last ten days of the month of Ramadhan."
 
In fact the whole month of Ramadhan is a period of spiritual training wherein believers devote much of their time to fasting. Prayers, frequent recitations of the Holy Quran and remembrance of Allah, as well as charity and goodwill, but during the last ten days of the month they strive more to worship God Almighty and to do good deeds.
 
The believers gather in the mosque in large numbers for Prayers and spend these nights in remembrance of Allah, asking forgiveness for their shortcomings and looking for the blessed night with the firm belief that God accepts the prayers of the supplicant readily during this night.
 
Those who can afford to devote the whole of their time in the remembrance of Allah, stay in the mosque for ten days. This worship is called I'tikaf or Retreat. They observe fast during the day and occupy themselves with the remembrance of Allah, performing voluntary Prayers and studying the Holy Quran, day and night, apart from the obligatory Prayers which they perform with the congregation. Food and other necessities of life are provided for them during their stay in the mosque, thus they my not leave the precincts of the mosque except for a genuine religious purpose.
 
Devoting their time thus fully to the remembrance of Allah, they hope to receive the divine favors and blessings connected with the blessed night.
 
The Holy Prophet, peace be upon him, was very particular in this regard. It is related that when the last ten days of Ramadhan began, he used to keep awake the whole night and was most diligent in worship.
 
Ayesha, the wife of the Holy Prophet, once asked him, "Messanger of Allah, tell me, in case I should realize which night is the Night of Decree, how should I supplicate in it? He answered: Supplicate; Allah, Thou art Most Forgiving and does love forgiveness, the do Thou forgive me' (Tirmidhi)