Sunan an-Nasa'i 5238
سنن النسائي#5238Sahihأَخْبَرَنَا مُحَمَّدُ بْنُ سَلَمَةَ، قَالَ حَدَّثَنَا ابْنُ وَهْبٍ، عَنْ يُونُسَ، عَنِ الزُّهْرِيِّ، عَنْ عُبَيْدِ اللَّهِ بْنِ عَبْدِ اللَّهِ، عَنِ ابْنِ عَبَّاسٍ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم كَانَ يَسْدُلُ شَعْرَهُ وَكَانَ الْمُشْرِكُونَ يَفْرُقُونَ شُعُورَهُمْ وَكَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم يُحِبُّ مُوَافَقَةَ أَهْلِ الْكِتَابِ فِيمَا لَمْ يُؤْمَرْ فِيهِ بِشَىْءٍ ثُمَّ فَرَقَ رَسُولُ اللَّهِ صلى الله عليه وسلم بَعْدَ ذَلِكَ .
It was narrated from Ibn 'Abbas that:The Messenger of Allah [SAW] used to let his hair hang down (without a parting) and the Mushrikun used to part their hair. The Messenger of Allah [SAW] liked to act in accordance with the People of the Book, in matters where no specific command had been given to him. Then the Messenger of Allah [SAW] parted his hair after that
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:
In-book reference: 48:199