Musnad Ahmad 1153:2021

Mu'adh narrated to us, he said: Humayd al-Tawil narrated to us, from Abdullah ibn Shaqiq al-'Uqayli, who said: I asked Aisha about the prayer of the Messenger of Allah, peace and blessings of Allah be upon him, at night. She said: "He used to pray a long night standing, and a long night sitting. And when he recited while standing, he would bow while standing, and when he recited while sitting, he would bow while sitting."