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.)