Musannaf Ibn Abi Shayba 37:536

Al-Fadl ibn Dukayn and Abu Dawud narrated to us, from Yasin al-Ijli, from Ibrahim ibn Muhammad ibn al-Hanafiyyah, from his father, from Ali, from the Prophet, peace be upon him, he said: The Messenger of Allah, peace be upon him, said: "The Mahdi is from us, the People of the House; Allah will rectify him in a single night."