Musnad Abu Ya'la al-Mawsili 129:68

Ibrahim ibn al-Hajjaj narrated to us, Hammad narrated to us, from Humayd, that Anas was asked about the hair of the Prophet, may Allah bless him and grant him peace. He said: "The hair of the Messenger of Allah, may Allah bless him and grant him peace, did not exceed his ears; it was as if it were the hair of Qatadah." Qatadah rejoiced on that day, and the hair of Qatadah was curly.