Abd al-Aziz narrates from his father Utbah that his father, Sayyiduna Salim (may Allah be pleased with him), came as a delegate to the Messenger of Allah (peace and blessings be upon him) while he was a young boy. The Messenger of Allah (peace and blessings be upon him) invoked blessings for him (tashmit) and supplicated for him, and he purified himself (performed ablution) with the water left over from his (peace and blessings be upon him) ablution. On that day he had a lock of hair on his head, and he had reached puberty, or was close to it.
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 6351