It was narrated on the authority of ‘Uyaynah ibn ‘Abdul-Rahmaan that his father said:
The Night of Al-Qadr was mentioned in the presence of Abu Bakrah who said, "I am not going to seek it because of something I heard from the Prophet except in the last ten days [of Ramadan]. I heard the Prophet say, 'Seek it in the last nine nights, or seven nights, or five nights, or three nights or the last night.'" Abu Bakrah used to perform prayer during the first twenty nights of Ramadan as he would usually pray during the whole year, but when the last ten nights came, he would be extra diligent. [At-Tirmithi: Hasan Saheeh] [At-Tayaalisi, Ahmad, An-Nasaa’i, Al-Bazzaar and At-Tabaraani]
It was narrated on the authority of Mu‘aawiyah ibn Abu Sufyaan, may Allah be pleased with him, that the Prophet, , said: "Seek the Night of Al-Qadr in the last night [of Ramadan]." [Ibn Khuzaymah] [Al-Albaani: Saheeh]
Ibn Khuzaymah wrote a title for this Hadeeth, "Chapter: On the order to seek the Night of Al-Qadr in the last night of Ramadan - and it may occur in the last night in some years."
Benefits and rulings:
First: The Night of Al-Qadr occurs in the last ten nights of Ramadan, most probably in the odd-numbered nights. Therefore, the Muslim should seek it throughout the ten nights.
Second: The Companions, may Allah be pleased with them, were keen to seek the Night of Al-Qadr and fill it with voluntary prayers.
Third: The Night of Al-Qadr may come in the last night in some years, since the Hadeeths showed that the exact night may change.
Fourth: The Muslim should not quit praying, reciting the Quran, performing the Taraaweeh after the 27th of Ramadan or after the Imaam completes the recitation of the Quran in the Taraaweeh because he is supposed to be seeking the Night of Al-Qadr which may be the last night of the month.