Sunan an-Nasa'i 5233
سنن النسائي#5233Sahihأَخْبَرَنَا حَاجِبُ بْنُ سُلَيْمَانَ، عَنْ وَكِيعٍ، عَنْ سُفْيَانَ، عَنْ أَبِي إِسْحَاقَ، عَنِ الْبَرَاءِ، قَالَ مَا رَأَيْتُ مِنْ ذِي لِمَّةٍ أَحْسَنَ فِي حُلَّةٍ مِنْ رَسُولِ اللَّهِ صلى الله عليه وسلم وَلَهُ شَعْرٌ يَضْرِبُ مَنْكِبَيْهِ .
It was narrated that Al-Bara' said:"I never saw any long haired man in a Hullah who was more handsome than the Messenger of Allah [SAW], and he had hair that came down to his shoulders
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiSahih Muslim
In-book reference: 48:194