Musnad Ahmad 937:58

Yahya narrated to us, from Sufyan, Sulayman narrated to us, from Mujahid, from Ibn Abi Layla, from Abu Dharr, from the Prophet, peace and blessings of Allah be upon him, who said: "Shall I not guide you to a treasure from the treasures of Paradise? There is no power and no strength except by Allah."