Musnad Ahmad 25:407

Ishaq ibn Yusuf narrated to us, Abd al-Malik narrated to us, from Ata, from Ibn Abbas, that he came to his maternal aunt Maymunah, the wife of the Prophet, may Allah bless him and grant him peace. He said: "The Messenger of Allah, may Allah bless him and grant him peace, stood up at night to a water skin and performed ablution, then he stood and prayed." He said: "And I stood and performed ablution, then I stood to his left." He said: "So he took my hand and turned me from behind him until he positioned me to his right."