Riyad as-Salihin (The Meadows of the Righteous)
by Imam Nawawi
294. Chapter: On the prohibition against a man or woman dyeing their hair black
1637. Jabir said, "Abu Quhafa, the father of Abu Bakr as-Siddiq, was brought on the day of the conquest of Makka with his head and beard pure white. The Messenger of Allah, may Allah bless him and grant him peace, said, 'Change this, but avoid black.'" [Muslim]
