Shama-il Tirmidhi Chapter 1, Hadith Number 1 (1).
The hair of Rasullullah (Sallallahu alaihe wasallam) was neither very straight nor very curly (but slightly wavy). When he attained the age of forty, Allah the Almighty granted him nubuwwah (prophethood).He lived for ten years in Makkah (commentary) and in Madina for ten years. At that time there were not more than twenty white hair on his mubarak (blessed) head and beard.” (This will be described in detail in the chapter on white hair of Rasulullah (Sallallahu alaihe wasallam).
Commentary:
It is stated in the hadeeth under discussion that Sayyidina Rasullullah (Sallallahu alaihe wasallam) lived for ten years in Makkah Mukarramah after nubuwwah (prophethood). For this reason it is stated that he attained the age of sixty years. This is contrary to what has been reported in the other ahaadith, where it is stated that Sayyidina Rasullullah (Sallallahu alaihe wasallam) lived there for thirteen years and attained the age of sixty three years. In some ahaadith it is stated that Sayyidina Rasullullah (Sallallahu alaihe wasallam) attained the age of sixty five years. At the end of this kitaab all three ahaadith will be quoted. Imaam Bukhari (R.A.) says:
“Most narrations show that Rasullullah (Sallallahu alaihe wasallam) lived for sixty three years.” The ulama (scholars) have summed up these ahaadith in two ways. First, that Sayyidina Rasullullah (Sallallahu alaihe wasallam) received nubuwwah (prophethood) at the age of forty and risaalah three years thereafter, and after that he lived for ten years in Makkah Mukaraamah. According to this, the three years between nubuwwah and risaalah have been in the hadeeth under discussion.