حَدَّثَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، حَدَّثَنَا خَالِدُ بْنُ الْحَارِثِ، وَابْنُ أَبِي عَدِيٍّ، عَنْ حُمَيْدٍ، قَالَ سُئِلَ أَنَسُ بْنُ مَالِكٍ أَخَضَبَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ قَالَ إِنَّهُ لَمْ يَرَ مِنَ الشَّيْبِ إِلاَّ نَحْوَ سَبْعَةَ عَشَرَ أَوْ عِشْرِينَ شَعَرَةً فِي مُقَدَّمِ لِحْيَتِهِ ‏.‏

It wasnarrated that Humaid said: “Anas bin Malik was asked: ‘Did theMessenger of Allah (PBUH) dye his hair?’ He said: ‘He did not haveanywhite hair apart from approximately seventeen or twenty hairs atthefront of his beard.’” Translation Not Available

Book Ref: Sunan Ibn Majah Book 32 Hadith 3629
Web Ref:  Sunan Ibn Majah Vol 4 Book 32 Hadith 3629