Shab-e-Qadr (the night of Qadr) is a highly virtuous night since the Holy Quran was transferred on the holy heart of the Prophet(pbuh) from LOH-E-MEHFOOZ (the Preserved Tablet) to the earth in this night.
Messenger of ALLAH (Blessings of Allah and peace be on him) told us to search for Shab-e-Qadr in the odd numbered nights, in the last ten days of Ramdan. So, the 21st, 23rd, 25th, 27th or 29th night of Ramadan could be Shab-e-Qadr.
The prayers of one night of Shab-e-Qadr are stated to be better thatn the prayers of one thousand nights. It is the night during which the events of the next year are determined and Angels descend on earth thorughout the nigh and visit the Imam-al-Asr waz-Zaman Imam Mehdi(a.s.). Each momin and momina has been suggested to wake up and pray, recite the Holy Quran and ask for the betterment of the current and the life hereafter.
The night is so full of holiness that even the angels in the heavens see it as worthy of witnessing.
It is reported by Abi Hatim, Al Wahidi, and Mujahid, that the Messenger, salla Allahu alahi wa sallam, spoke of a man amongst the Israelites who devoted a thousand years of his life to the worship of Allah.
The Companions were amazed yet saddened because they knew that they could not attain such a level of devotion. So Allah, subhana wa talla, through His mercy, informed them of the Night of Power which is equivalent to a thousand months.
Qadr also means to maintain, appoint, assign, or decree an order. On this night, Allah, subhana wa talla informs the angels of His commands and orders for the universe. This is also the night of honor and prestige which a faithful servant is rewarded with.
All his or her good deeds will be multiplied through the mercy of Allah.
In a hadith related by Abu Hurairah, radiua Allahu anhu, the Messenger of Allah, sala Allahu alahi wa sallam, said:
“He who spends the night in prayer on the Night of Power, as a sign of His faith, andseeking rewards from Allah, his previous sins will be forgiven.”
(Bukhari/Muslim)
This hadith indicates that whether a person is aware of the night or not, Allah will forgive him his past sins.