Musnad Ahmad 928:15

Muhammad ibn Ja‘far narrated to us, Shu‘bah narrated to us, he said: I heard ‘Abdah ibn Abi Lubabah narrating from Zirr ibn Hubaysh, he said: Ubayy said: "The Night of Decree, by Allah, I indeed know it." Shu‘bah said: "And the majority of my knowledge is: 'It is the night which the Messenger of Allah, may Allah bless him and grant him peace, commanded us to stand in prayer, it is the night of the twenty-seventh.'" Shu‘bah was only doubtful regarding this phrase: "It is the night which the Messenger of Allah, may Allah bless him and grant him peace, commanded us." He said: "And a companion of mine narrated it to me from him."