When did the Prophet (peace be upon him) say: "I am the Prophet, no lie, I am the son of Abd al-Muttalib"?

That was during the Battle of Hunayn in the eighth year of the Hijra, when the Messenger of Allah, peace and blessings be upon him, did not turn back on that day. Abu Sufyan ibn al-Harith was holding the bridle of his mule. When the polytheists surrounded him, the Prophet, peace and blessings be upon him, dismounted and began to say: "I am the Prophet, no lie; I am the son of Abdul Muttalib." No one was seen on that day more resolute than him.