Musnad Abu Ya'la al-Mawsili 3:114

Abu Musa Muhammad ibn al-Muthanna narrated to us, Abu Bakr ibn Ayyash narrated to us, Abu Ishaq narrated to us, from Hubayrah ibn Barim, from Ali, who said: The Messenger of Allah (peace and blessings of Allah be upon him) used to wake his family during the last ten nights, and he would raise the curtains.