Musnad Ahmad 5:732

Abdullah narrated to us, Nasr ibn Ali narrated to me, Nuh ibn Qays narrated to us, Khalid ibn Khalid narrated to us, from Yusuf ibn Mazin: That a man asked Ali and said, "O Commander of the Faithful, describe the Messenger of Allah, may Allah bless him and grant him peace, for us." He said: "He was not excessively tall, nor was he short; he was above medium height. When he walked with people, he would tower over them. He was white with a bright complexion, had a large head, a radiant forehead, and a wide space between his eyebrows. He had long eyelashes, and his palms and feet were thick/fleshy. When he walked, he would lift his feet as if he were descending a slope. The sweat on his face was like pearls. I have not seen anyone like him before or after him. May my father and mother be sacrificed for him, may Allah bless him and grant him peace."