Narrated Abu Imran: Anas looked at the people wearing Tailsans (i.e. a special kind of head covering worn by Jews in old days). On that Anas said, "At this moment they (i.e. those people) look like the Jews of Khaibar."
— Sahih Bukhari, Volume 5, Book 59: Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi), Hadith #519