Sahih al-Bukhari, Book 77, Hadith 114 (In-Book) ⓘ
Narrated `Uthman bin `Abdullah bin Mauhab: I went to Um Salama and she brought out for us some of the dyed hair of the Prophet.
حَدَّثَنَا مُوسَى بْنُ إِسْمَاعِيلَ، حَدَّثَنَا سَلاَّمٌ، عَنْ عُثْمَانَ بْنِ عَبْدِ اللَّهِ بْنِ مَوْهَبٍ، قَالَ دَخَلْتُ عَلَى أُمِّ سَلَمَةَ فَأَخْرَجَتْ إِلَيْنَا شَعَرًا مِنْ شَعَرِ النَّبِيِّ صلى الله عليه وسلم مَخْضُوبًا.
also referenced under: Hadith 5897 (DarusSalam) & Volume 7, Book 72, Hadith 785 (USC-MSA)