Jabir b. Samura reported that there had appeared some whiteness on the front part of the head and beard of Allah's Messenger (ﷺ). When he applied oil, it did not become visible, but when he did not (apply) oil, it became apparent. And he had a thick beard. A person said:His face was as (bright) as the sword. Thereupon he (Jabir) said: No, it was round and like the sun and the moon. And I saw the seal near his shoulder of the size of a pigeon's egg and its color was the same as that of his body
Hadith 6085 — Sahih Muslim 43:143
حَدَّثَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، حَدَّثَنَا مُحَمَّدُ بْنُ جَعْفَرٍ، حَدَّثَنَا شُعْبَةُ، عَنْ سِمَاكٍ، قَالَ سَمِعْتُ جَابِرَ بْنَ سَمُرَةَ، قَالَ رَأَيْتُ خَاتِمًا فِي ظَهْرِ رَسُولِ اللَّهِ صلى الله عليه وسلم كَأَنَّهُ بَيْضَةُ حَمَامٍ .
Jabir. Samura reported:I saw the seal on his back as if it were a pigeon's egg
As-Sa'ib b. Yazid reported:My mother's sister took me to Allah's Messenger (ﷺ) and said: Allah's Messenger, here is the son of my sister and he is ailing. He touched my head and invoked blessings upon me. He then performed ablution and I drank the water left from his ablution; then I stood behind him and I saw the seal between his shoulders
Abdullah b. Sarjis reported:I saw Allah's Apostle (ﷺ) and ate with him bread and meat, or he said Tharid (bread soaked in soup). I said to him: Did Allah's Apostle (ﷺ) seek forgiveness for you? He said: Yes, and for you, and he then recited this verse:" Ask forgiveness for thy sin and for the believing men and believing women" (xlvii. 19). I then went after him and saw the Seal of Prophethood between his shoulders on the left side of his shoulder having spots on it like moles
Anas b. Malik reported that Allah's Messenger (ﷺ) was neither very conspicuously tall nor short-statured, and his color was neither glaringly white nor brown; his hair was neither very curly nor very straight; Allah commissioned him (as a Prophet) when he had reached the age of forty years, and he stayed in Mecca for ten years and for ten years in Medina; Allah took him away when he had just reached the age of sixty, and there had not been twenty white hair in his head and beard
Anas b. Malik reported that Allah's Messenger (ﷺ) died when he was sixty-three years old, and so was the case with Abu Bakr, and so was the case with Umar who was also sixty-three (when he died)
A'isha reported that Allah's Messenger (ﷺ) died when he had attained the age of sixty-three. And a hadith like this had been transmitted on the authority of Sa'id b. Musayyib