Sunan an-Nasa'i, Volume 6, Book 48, Hadith 5063 (DarusSalam) ⓘ
It was narrated that Al-Bara' said: "I have never seen anyone who looked more handsome in a red Hullah than the Messenger of Allah [SAW], with his long hair that came down to his shoulders."
أَخْبَرَنَا مُحَمَّدُ بْنُ عَبْدِ اللَّهِ بْنِ عَمَّارٍ، قَالَ حَدَّثَنَا الْمُعَافَى، عَنْ إِسْرَائِيلَ، عَنْ أَبِي إِسْحَاقَ، عَنِ الْبَرَاءِ، قَالَ مَا رَأَيْتُ أَحَدًا أَحْسَنَ فِي حُلَّةٍ حَمْرَاءَ مِنْ رَسُولِ اللَّهِ صلى الله عليه وسلم وَجُمَّتُهُ تَضْرِبُ مَنْكِبَيْهِ .
also referenced under: Hadith 5060 (Reference) & Book 48, Hadith 21 (In-Book)