Musannaf Ibn Abi Shayba 3:2407

Waki’ narrated to us, from Aflah, from al-Qasim, who said: We used to come to ‘Aisha before the dawn prayer. We came to her one day, and behold, she was praying. She said: "I slept through my portion [of nightly worship] this night, and I would not leave it."