Musannaf Ibn Abi Shayba 1:232

Waki’ ibn al-Jarrah narrated to us, from al-Rabi’ ibn Sulaym, from Abu Labid, who said: I saw Ali come to the *ghait* (open field/toilet area) on a mule, wearing an *izar* (lower garment), a *rida* (upper garment), a turban, and two leather socks. I saw him urinate, then he performed ablution. He removed the turban, and I saw his head like the palm of my hand, upon it was hair like the lines of fingers. He wiped his head, then he wiped over his two leather socks.