However, that is not to say that all chengyu are born of an often-told fable. Indeed, chéngyǔ which are free of metaphorical nuances exist, although the boundary between a chéngyǔ and fossilized four-character expressions from Literary Chinese that continue to be used in the vernacular language can sometimes be blurry. An example of this is ("yán ér wú xìn", lit: "speaking, yet without trust"), referring to an individual who cannot be trusted despite what he says, an essentially deceitful person. This particular example comes from a revered classic, the "Analects of Confucius" (, "Lúnyŭ"), so its status as a chéngyǔ is generally acknowledged. The idiom itself is not derived from a specific occurrence from which a moral may be explicitly drawn; instead, it is succinct in its original meaning and would likely be intelligible to an individual learned in formal written Chinese. Its archaic nature is only betrayed by the now-unusual use of the character "yán" () as a verb.