Musnad Ahmad 907:192

'Abd al-Razzaq narrated to us, Isra'il informed us, from Simak, that he heard Jabir ibn Samurah saying: "The Messenger of Allah (peace and blessings of Allah be upon him) had gray hairs at the front of his head and his beard. When he oiled and combed his hair, it was not apparent, but when his hair was disheveled, it was apparent. He had a lot of hair on his head and beard." A man said: "Was his face like a sword?" He said: "No, rather it was like the sun and the moon, round." He said: "And I saw his seal (the Seal of Prophethood) near his shoulder, like a pigeon's egg, resembling his body."