Abu Dawud
Clothing
Book Number: 027 / Hadith Number: 4067
Narated By Ali ibn Rukanah : Ali quoting his father said: Rukanah wrestled with the Prophet (pbuh) and the Prophet (pbuh) threw him on the ground. Rukanah said: I heard the Prophet (pbuh) say: The difference between us and the polytheists is that we wear turbans over caps.