إلا أنها لما كانت كالأصل للمجاز
Yet literal usage is, as it were, the foundation for figurative usage.
Figurative expression presupposes an established meaning and an identifiable departure from that use. Without determining the original assignment, one might confuse figurative language with a mistake or an unfamiliar but literal sense.
For instance, “asad” used for a lion accords with its usual lexical assignment. Applied to a brave human being, it may have a different rhetorical classification if a suitable indicator is present. Assignment versus actual use is thus the controlling distinction for the next discussions.