Musnad Ahmad 27:2014

He said: I read this hadith to my father, and I heard it through audition. He said: Al-Aswad ibn Amir narrated to us, Shu'bah narrated to us, Abdullah ibn Dinar said: He informed me, he said: I heard Ibn Umar narrating from the Prophet, peace and blessings of Allah be upon him, regarding the Night of Decree (Laylat al-Qadr). He said: "Whoever is seeking it, let him seek it on the night of the twenty-seventh." Shu'bah said: A trustworthy man mentioned to me from Sufyan that he used to say: He only said: "Whoever is seeking it, let him seek it in the remaining seven." Shu'bah said: I do not know if he said this or that; Shu'bah was in doubt. [Abdullah ibn Ahmad said]: My father said: The trustworthy man is Yahya ibn Sa'id al-Qattan.