The difficult thing to pick apart here is the writer's intention and the reader's reception and base of knowledge.

In particular a lot of imaginative literature is based on having a common level of shared context to get a potentially wider set of references and implied meanings which are almost never apparent in a surface reading. As a result literature may use phrases from other unmentioned sources which the author has read/knows, but which the reader is unaware. Those who read Western literature without any grounding in the stories within the Bible will often obviously be left out of the conversation which is happening, but which they won't know exists.

Indigenous knowledge bases have this same feature despite the fact that they're based on orality instead of literacy.