Shama-il Tirmidhi Chapter 052, Hadith Number 006 (367).

Anas Radiyallahu 'Anhu reports: "Rasulullah Sallallahu 'Alayhi Wasallam was not of a tall height nor was he short. (According to colour) he was not very white, nor very wheat coloured (dark). His mubaarak hair was not very curly nor very straight (but was slightly curled). He was blessed with prophethood at the age of forty, after that he lived for ten years in Makkah Mukarramah, and ten years in Madinah Munawwarah. At the age of sixty years Rasulullah Sallallahu 'Alayhi Wasallam passed away. At that time he did not have more than twenty white hair in his mubaarak head and beard".

Commentary
This hadith of Sayyidina Anas Radiyallahu 'Anhu has been mentioned at the beginning of the kitaab. In its commentary the three narrations have also been mentioned, and the explanations of the three different narrations have also been given. The 'ulama are unanimous in that the narrations where in the age of Sayyidina Rasulullah Sallallahu 'Alayhi Wasallam is narrated as sixty three years are the most correct. The other hadith can be referred to this, or it may be possible that the later narrators may have slipped up. Therefore in this hadith Sayyidina Anas Radiyallahu 'Anhu it could be explained that many a times, at the time of counting, only the units are mentioned, and the fractions omitted. Sayyidina 'Urwah bin Zubayr Radiyallhu 'Anhu, the nephew of Sayyidiyina 'Aayesha Radiyallahu 'Anha has stated that the narration of Sayyidina Ibn 'Ababas Radiyallahu 'Anhu where the age is mentioned as sixty five years is incorrect. Mulla Ali Qaari has explained this in detail.