Musnad Ahmad 534:26

Abu al-Nadr narrated to us, he said: Hariz ibn Uthman narrated to us, he said: I asked Abdullah ibn Busr, a companion of the Prophet, may Allah bless him and grant him peace: "Was the Prophet, may Allah bless him and grant him peace, an old man?" He said: "He was younger than that, but there were some white hairs in his beard—and perhaps he said in his lower lip hair."