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.
Sayyiduna Abu Bakrah (may Allah be pleased with him) narrates: Sayyiduna Jibril (peace be upon him) circumcised the Prophet (peace and blessings be upon him) at the time when he washed the heart of the Prophet (peace and blessings be upon him).
At-Tabarani recorded it in al-Mu'jam al-Awsat; its chain contains Abd al-Rahman bin Uyaynah and Salamah bin Muharib, and I do not know either of them; the remaining narrators are thiqat (trustworthy).