ENOfficial
‘Ubada reported God’s messenger as saying, “Keep to turbans, for they are the mark of the angels, and let hang down behind your backs.” Baihaqi transmitted it in Shu'ab al-iman.
Source: sunnah.com
Other translations
Arabic
وَعَنْ عُبَادَةَ رَضِيَ اللَّهُ عَنْهُ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «عَلَيْكُمْ بالعمائم فَإِنَّهَا سيماء الْمَلَائِكَة وأخوها خلف ظهوركم» . رَوَاهُ الْبَيْهَقِيّ
sunnah.com