Musnad Ahmad 1153:1166

'Abd al-Razzaq narrated to us, Ma'mar narrated to us, from al-A'mash, from Tamim ibn Salamah, from 'Urwah, from 'Aishah, she said: The Prophet, peace and blessings of Allah be upon him, used to pray during the night. When he finished, he would say to me: "Rise and pray the Witr."