Sahih Bukhari Volume 7, Book 77, Hadith 5902

حَدَّثَنَا إِسْمَاعِيلُ، قَالَ حَدَّثَنِي مَالِكُ بْنُ أَنَسٍ، عَنْ رَبِيعَةَ بْنِ أَبِي عَبْدِ الرَّحْمَنِ، عَنْ أَنَسِ بْنِ مَالِكٍ ـ رضى الله عنه ـ أَنَّهُ سَمِعَهُ يَقُولُ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم لَيْسَ بِالطَّوِيلِ الْبَائِنِ، وَلاَ بِالْقَصِيرِ، وَلَيْسَ بِالأَبْيَضِ الأَمْهَقِ، وَلَيْسَ بِالآدَمِ، وَلَيْسَ بِالْجَعْدِ الْقَطَطِ، وَلاَ بِالسَّبْطِ، بَعَثَهُ اللَّهُ عَلَى رَأْسِ أَرْبَعِينَ سَنَةً، فَأَقَامَ بِمَكَّةَ عَشْرَ سِنِينَ، وَبِالْمَدِينَةِ عَشْرَ سِنِينَ، وَتَوَفَّاهُ اللَّهُ عَلَى رَأْسِ سِتِّينَ سَنَةً، وَلَيْسَ فِي رَأْسِهِ وَلِحْيَتِهِ عِشْرُونَ شَعَرَةً بَيْضَاءَ‏.‏

Narrated By Anas bin Malik : The Prophet was neither conspicuously tall, nor short; neither, very white, nor tawny. His hair was neither much curled, nor very straight. Allah sent him (as an Apostle) at the age of forty (and after that) he stayed for ten years in Mecca, and for ten more years in Medina. Allah took him unto Him at the age of sixty, and he scarcely had ten white hairs on his head and in his beard.