Sunan Abi Dawud Book 2, Hadith 322
I used to sleep with my legs in front of the Messenger of Allah (ﷺ) when he would offer his prayer at night (i.e. tahajjud prayer offered towards the end of the night.). When he prostrated himself he struck my legs, and I drew them up and he then prostrated.
The Messenger of Allah (ﷺ) used to pray at night and she (‘A’ishah) would lie between him and the qiblah, sleeping on the bed on which he would sleep. When he wanted to offer the witr prayer, he awakened her and she offered the witr prayer.
"I used to be asleep while my legs would be in the front of the Messenger of Allah (ﷺ) while he was praying during the night. When he wanted to prostrate, he would prod my feet, so I would pull them up, and he would prostrate.