Musnad Ahmad 907:124

Abdullah narrated to us, Muhammad ibn Abi Ghalib narrated to me, Abd al-Rahman ibn Shurayk narrated to us, my father narrated to me, from Simak, from Jabir ibn Samurah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Seek Laylat al-Qadr in the last ten nights of Ramadan, on an odd night, for I have seen it and then I was made to forget it. It is a night of rain and wind," or he said: "A night of downpour and wind."