Sunan an-Nasa'i 5071
سنن النسائي#5071Sahihأَخْبَرَنِي الْحُسَيْنُ بْنُ حُرَيْثٍ، قَالَ أَنْبَأَنَا الْفَضْلُ بْنُ مُوسَى، عَنْ مَعْمَرٍ، عَنِ الزُّهْرِيِّ، عَنْ أَبِي سَلَمَةَ، عَنْ أَبِي هُرَيْرَةَ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " إِنَّ الْيَهُودَ وَالنَّصَارَى لاَ تَصْبُغُ فَخَالِفُوا عَلَيْهِمْ فَاصْبُغُوا " .
It was narrated that Abu Hurairah said:"The Messenger of Allah [SAW] said: 'The Jews and the Christians do not dye their hair, so be different from them and dye your hair
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: 48:32