Musnad Ahmad 1153:1856

Abu Mu'awiyah narrated to us, he said: Al-A'mash narrated to us, from Ibrahim, from Al-Aswad, from Aisha, she said: "It is as if I am looking at the glistening of the perfume in the parting of the hair of the Messenger of Allah, may Allah bless him and grant him peace, while he was in the state of Ihram."