Is there an authentic Hadith in which the Quraysh infidels called Muhammad "the Trustworthy, the Faithful," or are prophets infallible from the sins that Christians accuse them of?

Al-Suyuti mentioned that the Prophet, peace and blessings be upon him, was known among his people in his youth for his excellent chivalry and character, and that he was nicknamed "Al-Amin" (the Trustworthy) due to his truthfulness and honesty. Al-Qurtubi narrated that Abu Jahl knew of the Prophet's truthfulness, peace and blessings be upon him, but refrained from following him out of fear of what people would say. As for the infallibility of prophets, scholars agree on their infallibility from major sins, but they differed concerning minor sins. Some believe that minor sins might occur from them, but Allah grants them success in repentance, and they are purified from treachery and incest.