Mishkat al-Masabih 476
As-Sa'ib b. Yazid said:
My maternal aunt took me to the Prophet and said, “My nephew is ill.” So he wiped my head, invoked a blessing on me, then performed ablution, and I drank some of the water he had used. Then I stood up behind his back and looked at the seal of prophecy between his shoulders, like the button on a bride’s pavilion.

(Bukhari and Muslim.)
وَعَن السَّائِب بن يزِيد قَالَ: ذَهَبَتْ بِي خَالَتِي إِلَى النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فَقَالَتْ يَا رَسُولَ اللَّهِ إِنَّ ابْنَ أُخْتِي وَجِعٌ فَمَسَحَ رَأْسِي وَدَعَا لي بِالْبَرَكَةِ ثُمَّ تَوَضَّأَ فَشَرِبْتُ مِنْ وَضُوئِهِ ثُمَّ قُمْتُ خَلْفَ ظَهْرِهِ فَنَظَرْتُ إِلَى خَاتَمِ النُّبُوَّةِ بَين كَتفيهِ مثل زر الحجلة