Sunan Abi Dawud Book 2, Hadith 321
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 was sleeping in front of the Prophet (ﷺ) with my legs between him and the qiblah. Shu'bah said: I think she said: I was menstruating.
Abu Dawud said: This tradition has been narrated by al-Zuhri, 'Ata, Abu Bakr b. Hafs, Hisham b. 'Urwah, 'Irak b. Malik, Abu al-Aswad and Tamim b. Salamah; all transmitted from 'Urwah on the authority of 'Aishah. Ibrahim narrated from al-Aswad on the authority of 'Aishah. Abu al-Duha narrated from Masruq on the authority of 'Aishah. Al-Qasim b. Muhammad and Abu Salamah narrated it from 'Aisha. All these narrators did not mention the words "And I was menstruating."
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.