Do not pluck out grey hair, for it is the light of the Muslim on the Day of Judgment
Authentic hadithعن عمرو بن شعيب، عن أبيه، عن جده رضي الله عنه عن النبي صلى الله عليه وسلم قال: «لا تَنْتِفُوا الشَّيْبَ؛ فإنه نُور المسلم يوم القيامة».
‘Amr ibn Shu‘ayb (may Allah be pleased with him) reported from his father and grandfather that the Prophet (may Allah's peace and blessings be upon him) said: "Do not pluck out grey hair, for it is the light of the Muslim on the Day of Judgment.”
Explanation
The Prophet (may Allah's peace and blessings be upon him) forbade plucking grey hairs, whether they are on one's head or beard or any other place on the body, as this grey hair will be light for the person on the Day of Judgment.
Source · Narrated by Ibn Majah - Narrated by At-Termedhy - An-Nasaa’i - Narrated by Abu Daoud
From the Hadith Encyclopedia (hadeethenc.com).