Sunan an-Nasa'i 5241
سنن النسائي#5241Sahihأَخْبَرَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ، قَالَ حَدَّثَنَا سُفْيَانُ، عَنِ الزُّهْرِيِّ، عَنْ أَبِي سَلَمَةَ، وَسُلَيْمَانَ بْنِ يَسَارٍ، أَنَّهُمَا سَمِعَا أَبَا هُرَيْرَةَ، يُخْبِرُ عَنْ رَسُولِ اللَّهِ صلى الله عليه وسلم قَالَ " إِنَّ الْيَهُودَ وَالنَّصَارَى لاَ يَصْبُغُونَ فَخَالِفُوهُمْ " .
Abu Hurairah narrated that :The Messenger of Allah [SAW] said: "The Jews and the Christians do not dye their hair, so be different from them
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 ZaiHasan
In-book reference: 48:202