Responsa su Ecclesiaste 7:20

And I have wondered many times if it is even possible that a person in the history of the world has fully fulfilled this verse. Perhaps this idea is included in what King Shlomo said, “There is no righteous person in the world who does only good and no wrong” (Kohelet 7:20) - which means to say that even if his deeds were all good [in the eyes of G-d], it is impossible to not sin in the second way, regarding fulfilling the obligation [to be innocent in the eyes of] people.