Musannaf Ibn Abi Shayba 3:6306

Shababa narrated to us, from Layth ibn Sa'd, from Yazid ibn Abi Habib, from 'Abdullah ibn al-Harith, from 'Abdullah ibn Unays, the companion of the Messenger of Allah (may Allah bless him and grant him peace), that he was asked about the Night of Decree (Laylat al-Qadr). He said: I heard the Messenger of Allah (may Allah bless him and grant him peace) saying: "Seek that night on the night of the twenty-third."