Abu Dawud
Prayer
Book Number: 002 / Hadith Number: 1382
Narated By 'Abd Allah b. 'Umar : The Apostle of Allah (pbuh) was asked about lailat al-qadr an I was hearing. He said: It is during the whole of Ramadhan.
Abu Dawud said: Sufyan and Shu'bah narrated this tradition from Abu Ishaq as a statement of Ibn 'Umar himself; they did not transmit it as a saying of the Prophet (pbuh).