Musnad Ahmad 1153:1790

Hajjaj narrated to us, Layth narrated to us, he said: Uqayl narrated to me, from Ibn Shihab, from Urwah, from Aisha, that she informed him: That the Messenger of Allah (peace and blessings of Allah be upon him) delayed the night prayer (al-atamah) one night, and he mentioned its meaning.