Sayyiduna Abdullah bin Hilal al-Ansari (may Allah be pleased with him) narrates: My father took me to the Prophet (peace and blessings be upon him) and submitted: "O Messenger of Allah! Pray for him." The narrator says: I have not forgotten that the Prophet (peace and blessings be upon him) placed his hand on my head, so much so that I felt its coolness, until the Prophet (peace and blessings be upon him) prayed for blessing for me. The narrator states: I saw him; the hair of his head and beard was white, and because of old age he could not part the hair of his head. He used to keep voluntary fasts in the daytime and offer voluntary prayers at night.
Al-Tabarani recorded it, and its chain is hasan (good).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب المناقب / 16098