Musnad Ahmad 32:542

Hassan narrated to us, Hammad bin Salamah narrated to us, from Thabit al-Bunani, from Anas bin Malik, who said: "When the Messenger of Allah (peace and blessings of Allah be upon him) wanted the barber to shave his head, Abu Talha took the hair of one side of his head with his hand, and he took his hair and brought it to Umm Sulaym." He said: "And Umm Sulaym used to mix it into her perfume."