Sahih Muslim Book - 43, Hadith - 6100

وحَدَّثَنِي ابْنُ مِنْهَالٍ الضَّرِيرُ ، حَدَّثَنَا يَزِيدُ بْنُ زُرَيْعٍ ، حَدَّثَنَا يُونُسُ بْنُ عُبَيْدٍ ، عَنْ عَمَّارٍ ، مَوْلَى بَنِي هَاشِمٍ ، قَالَ : سَأَلْتُ ابْنَ عَبَّاسٍ : كَمْ أَتَى لِرَسُولِ اللهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَوْمَ مَاتَ ؟ فَقَالَ : مَا كُنْتُ أَحْسِبُ مِثْلَكَ مِنْ قَوْمِهِ يَخْفَى عَلَيْهِ ذَاكَ ، قَالَ قُلْتُ : إِنِّي قَدْ سَأَلْتُ النَّاسَ فَاخْتَلَفُوا عَلَيَّ ، فَأَحْبَبْتُ أَنْ أَعْلَمَ قَوْلَكَ فِيهِ ، قَالَ : أَتَحْسُبُ ؟ قَالَ قُلْتُ : نَعَمْ ، قَالَ : أَمْسِكْ أَرْبَعِينَ ، بُعِثَ لَهَا خَمْسَ عَشْرَةَ بِمَكَّةَ يَأْمَنُ وَيَخَافُ ، وَعَشْرَ مِنْ مُهَاجَرِهِ إِلَى الْمَدِينَةِ.

It was narrated that ‘Ammar, the freed slave of Banu Hashim, said: “I asked Ibn ‘Abbas: ‘How old was the Messenger of Allah (s.a.w) on the day he died?’ He said: ‘I did not think that a man of such standing among his people as you would be unaware of that.”’ He said: “I said: ‘I asked the people and they gave me different answers. I want to know what you say.’ He said: ‘Do you know how to count?’ I said: ‘Yes.’ He said: ‘Bear in mind that he was sent as a Prophet when he was forty. Fifteen years in Makkah, in it were times of safety and times of fear, and then years after he migrated to Al-Madinah.”’