Musnad Ahmad 1153:944

'Abd al-Razzaq narrated to us, he said: Sufyan informed us, from Hisham ibn 'Urwah, from his father, from 'Aishah, she said: "The Prophet, may Allah bless him and grant him peace, would not recite in any of the night prayer while sitting, until he reached old age. And when thirty or forty verses remained for him, he would stand and recite them, then he would prostrate."