Musannaf Ibn Abi Shayba 3:6112

Abu al-Ahwas narrated to us, from Sa'id, from Masruq, from Salamah ibn Kuhayl, from Abu Rashid, from Kurayb, the freed slave of Ibn Abbas, from Ibn Abbas, who said: I spent the night at my maternal aunt Maymunah’s house, and the Messenger of Allah (peace and blessings of Allah be upon him) spent the night there. I saw him stand up during the night and pray either eleven rak'ahs or thirteen rak'ahs.