The Messenger of Allah ﷺ forbade plucking out gray hair and said, "It is the light of the believer."
حدثنا أبو بكر بن أبي شيبة حدثنا عبدة بن سليمان عن محمد بن إسحق
نهى رسول الله ﷺ عن نتف الشيب وقال هو نور المؤمن
[Hasan] Tirmidhi reported it in the Book of Manners, chapter on the prohibition of plucking out grey hair, no. 2821, from the hadith of Abdah, with this wording. He said, This is a hasan hadith, and it was reported by Abdul-Rahman bin Harith and several others from Amr bin Shuayb.