Sahih al-Bukhari 3546
Narrated Hariz bin `Uthman:
That he asked `Abdullah bin Busr (i.e. the companion of the Prophet), "Did you see the Prophet (ﷺ) when 
he was old?" He said, "He had a few white hairs between the lower lip and the chin."
حَدَّثَنَا عِصَامُ بْنُ خَالِدٍ، حَدَّثَنَا حَرِيزُ بْنُ عُثْمَانَ، أَنَّهُ سَأَلَ عَبْدَ اللَّهِ بْنَ بُسْرٍ صَاحِبَ النَّبِيِّ صلى الله عليه وسلم قَالَ أَرَأَيْتَ النَّبِيَّ صلى الله عليه وسلم كَانَ شَيْخًا قَالَ كَانَ فِي عَنْفَقَتِهِ شَعَرَاتٌ بِيضٌ‏.‏