Musnad Abu Ya'la al-Mawsili 150:126

'Abd al-A'la narrated to us, Sufyan ibn 'Uyaynah narrated to us, from Salim Abu al-Nadr, from Abu Salamah, from 'Aishah, who said: "When I was awake, he would speak to me, and when I was asleep, he would lie down." Meaning: When the Prophet, may Allah bless him and grant him peace, would perform the Witr prayer.