Musnad Ahmad 1153:2336

Ya'qub narrated to us, he said: My father narrated to us, from Muhammad ibn Ishaq, he said: Muhammad ibn Ja'far ibn al-Zubayr narrated to me, from 'Urwah ibn al-Zubayr, from 'Aishah, the wife of the Prophet, may Allah bless him and grant him peace, she said: "When I would part the hair of the Messenger of Allah, may Allah bless him and grant him peace, I would make a parting from the crown of his head, and I would let his forelock fall between his eyes."