ENOfficial
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."
Source: sunnah.com
Other translations
Arabic
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.
sunnah.com