Musnad Ahmad 1153:526

Abu al-Mughirah narrated to us, al-Awza'i narrated to us, he said: Usamah ibn Zayd narrated to me, he said: Zabban ibn 'Abd al-'Aziz narrated to me, he said: 'Umar ibn 'Abd al-'Aziz narrated to me, from 'Aishah, she said: "The Messenger of Allah (peace and blessings of Allah be upon him) used to pray in the chamber while I was in the house, and he would separate the shaf' (even) and the witr (odd) with a taslim that he would make us hear."