Musnad Ahmad 1012:7

Muhammad ibn Abi ‘Adi narrated to us, from Humayd, from Anas, from ‘Ubadah ibn al-Samit, who said: The Messenger of Allah, peace and blessings of Allah be upon him, came out to us, intending to inform us about the Night of Decree (Laylat al-Qadr), but two men were arguing. The Messenger of Allah, peace and blessings of Allah be upon him, said: "I came out intending to inform you about the Night of Decree, but two men argued, so it was lifted. Perhaps it is better for you, so seek it in the ninth, the seventh, or the fifth."