Sahih al-Bukhari, Hadith 4208 ⓘ
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."
حَدَّثَنَا مُحَمَّدُ بْنُ سَعِيدٍ الْخُزَاعِيُّ، حَدَّثَنَا زِيَادُ بْنُ الرَّبِيعِ، عَنْ أَبِي عِمْرَانَ، قَالَ نَظَرَ أَنَسٌ إِلَى النَّاسِ يَوْمَ الْجُمُعَةِ، فَرَأَى طَيَالِسَةً فَقَالَ كَأَنَّهُمُ السَّاعَةَ يَهُودُ خَيْبَرَ.
also referenced under: Book 64, Hadith 248 (In-Book) & Volume 5, Book 59, Hadith 519 (USC-MSA)