Sunan Ibn Majah, Hadith 3721 ⓘ
It was narrated from 'Amr bin Sh'uaib from his father, that his grandfather said: "The Messenger of Allah forbade plucking out white hairs and said: 'It is the light of the believer.'"
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا عَبْدَةُ بْنُ سُلَيْمَانَ، عَنْ مُحَمَّدِ بْنِ إِسْحَاقَ، عَنْ عَمْرِو بْنِ شُعَيْبٍ، عَنْ أَبِيهِ، عَنْ جَدِّهِ، قَالَ نَهَى رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ عَنْ نَتْفِ الشَّيْبِ وَقَالَ " هُوَ نُورُ الْمُؤْمِنِ " .
also referenced under: Book 33, Hadith 66 (In-Book) & Volume 5, Book 33, Hadith 3721 (DarusSalam)