Narrated As-Sa'ib:

My aunt took me to Allah's Apostle and said, "O Allah's Apostle! My nephew is- ill." The Prophet touched my head with his hand and invoked Allah to bless me. He then performed ablution and I drank of the remaining water of his ablution and then stood behind his back and saw "Khatam An-Nubuwwa" (The Seal of Prophethood) between his shoulders like a button of a tent.

حَدَّثَنَا إِبْرَاهِيمُ بْنُ حَمْزَةَ، حَدَّثَنَا حَاتِمٌ ـ هُوَ ابْنُ إِسْمَاعِيلَ ـ عَنِ الْجُعَيْدِ، قَالَ سَمِعْتُ السَّائِبَ، يَقُولُ ذَهَبَتْ بِي خَالَتِي إِلَى رَسُولِ اللَّهِ ﷺ فَقَالَتْ يَا رَسُولَ اللَّهِ إِنَّ ابْنَ أُخْتِي وَجِعٌ فَمَسَحَ رَأْسِي وَدَعَا لِي بِالْبَرَكَةِ، ثُمَّ تَوَضَّأَ فَشَرِبْتُ مِنْ وَضُوئِهِ وَقُمْتُ خَلْفَ ظَهْرِهِ فَنَظَرْتُ إِلَى خَاتَمِ النُّبُوَّةِ بَيْنَ كَتِفَيْهِ مِثْلَ زِرِّ الْحَجَلَةِ.