Narrated As-Sa'ib bin Yazid:
"My maternal aunt took me to the Prophet (ﷺ), and said: 'O Messenger of Allah! Indeed my nephew is in pain.' So he wiped over my head and supplicated for blessings for me. And he performed Wudu and I drank from the water of his Wudu. Then I stood behind his back, and I looked at the seal between his two shoulder blades, and it resembled the egg of a partridge. (JA)
English reference (JA): Vol. 1, Book 46, Hadith 3643 (JA)
Arabic reference (JA): Book 49, Hadith 4004 (JA)