Musannaf Ibn Abi Shayba 16:845

Abu Bakr narrated to us, he said: Ishaq bin Mansur narrated to us, from Ibrahim bin Sa'd, from Muhammad bin Ishaq, from Yahya bin 'Abbad, from his father, from 'Aisha, she said: I used to part the hair behind the crown of the head of the Messenger of Allah, may Allah bless him and grant him peace, then I would let the forelock hang down.