Musnad Ahmad 5:184

Waki’ narrated to us, Mas’udi informed us, from ‘Uthman ibn ‘Abdullah ibn Hurmuz, from Nafi’ ibn Jubayr ibn Mut’im, from ‘Ali, who said: "The Messenger of Allah (peace and blessings of Allah be upon him) was neither tall nor short. He had a large head and beard. He had thick palms and feet. His face was tinged with redness. He had a long line of hair [extending from the chest to the navel]. He had large joints. When he walked, he leaned forward as if he were descending from a slope. I have not seen anyone like him before him or after him, peace and blessings of Allah be upon him."