Sayyiduna Anas bin Malik (may Allah be pleased with him) narrates that the Prophet (peace and blessings be upon him) said: "Among the honour my Lord has granted me is that I was born circumcised, and no one has seen my private parts."
At-Tabarani recorded it in al-Mu'jam al-Saghir and al-Mu'jam al-Awsat; its chain contains Sufyan bin al-Fazari, who is accused regarding it.