Musnad Abu Ya'la al-Mawsili 150:108

Ahmad ibn Hatim narrated to us, Yusuf ibn al-Majishun narrated to us, my father informed me, from ‘Asim ibn ‘Umar ibn Qatadah, from his grandmother Rumaythah, who said: I spent the morning with ‘Aishah. When we reached the morning, she stood up and performed ghusl (ritual bath), then she entered a room of hers and closed the door behind me. I said, "O Mother of the Believers, I did not spend the morning with you except for the sake of this hour." She said, "Then enter." So I entered, and she prayed eight rak'ahs. I do not know whether their standing was longer, or their bowing, or their prostration. Then she turned to me and struck my thigh, then said, "O Rumaythah, I saw the Messenger of Allah praying them, and if my father were to be resurrected for me to abandon them, I would not abandon them."