Abu-al-Faraj Ibn Harun (Gregory Bar hebraeus). The book is entertaining stories (№ 221666)

Someone said:
The highest degree of rhetorical art is to be able to give the truth for a lie, and the lie for the truth and to get people to do things they don't want to do and not to do what they want. Thus it is necessary to persuade them that they acted willingly, without any coercion.