Musnad Ahmad 1153:1568

Yahya narrated to us, from Shu'bah, who said: Al-Hakam and Sulayman narrated to us, from Ibrahim, from Al-Aswad, from Aisha, who said: "I saw the perfume," one of them said: "on the head - or hair," and the other said: "on the parting of the Messenger of Allah, may Allah bless him and grant him peace, while he was in the state of Ihram."