My aunt took me to the Prophet ﷺ and said, "O Messenger of Allah ﷺ! This son of my sister has got a disease in his legs." So he passed his hands on my head and prayed for Allah's blessings for me; then he performed ablution and I drank from the remaining water. I stood behind him and saw the seal of Prophethood between his shoulders, and it was like the "Zir-al-Hijla" (means the button of a small tent, but some said 'egg of a partridge.' etc.) (Using translation from Bukhārī 190)  

سَمِعْتُ السَّائِبَ بْنَ يَزِيدَ يَقُولُ ذَهَبَتْ بِي خَالَتِي إِلَى رَسُولِ اللهِ ﷺ فَقَالَتْ «يَا رَسُولَ اللهِ إِنَّ ابْنَ أُخْتِي وُجِعَ فَمَسَحَ رَأْسِي وَدَعَا لِي بِالْبَرَكَةِ ثُمَّ تَوَضَّأَ فَشَرِبْتُ مِنْ وَضُوئِهِ ثُمَّ قُمْتُ خَلْفَ ظَهْرِهِ فَنَظَرْتُ إِلَى خَاتَمِهِ بَيْنَ كَتِفَيْهِ مِثْلُ زِرِّ الْحَجَلَةِ»