Sahih al-Bukhari 3548
صحيح البخاري#3548SahihNarrated Anas:Allah's Messenger (ﷺ) was neither very tall nor short, neither absolutely white nor deep brown. His hair was neither curly nor lank. Allah sent him (as an Apostle) when he was forty years old. Afterwards he resided in Mecca for ten years and in Medina for ten more years. When Allah took him unto Him, there were scarcely twenty white hairs in his head and beard
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 61:57