Musnad Ahmad 1153:2253

'Ali ibn 'Asim narrated to us, from 'Ata' ibn al-Sa'ib, from Ibrahim, from al-Aswad ibn Yazid, from 'Aisha, who said: "I saw 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."