Chapter 1: Purification (Kitab Al-Taharah)
Narrated A Man from the Companions: Humayd al-Himyari said: I met a man (Companion of the Prophet) who remained in the company of the Prophet (ﷺ) just as Abu Hurayrah remained in his company. He then added: The Messenger of Allah (ﷺ) forbade that anyone amongst us should comb (his hair) every day or urinate in the place where he takes a bath.
Sunan Abi Dawud 28