Musannaf Ibn Abi Shayba 16:833

Abu Bakr narrated to us, he said: Ishaq bin Sulayman narrated to us, from Jarir, from Abdullah bin Busr al-Sulami, who said: We came to him while we were young boys, and we did not know what to ask him about. So I said to him—or one of us said to him—"Was the Messenger of Allah (peace and blessings of Allah be upon him) a young man or an old man?" He said: "There were some white hairs in his *'anfaqah* (the hair between the lower lip and the chin)."