Know that the figures employed by prophets are of two kinds: first, where every word which occurs in the simile represents a certain idea: and secondly, where the simile, as a whole, represents a general idea, but has a great many points which have no reference whatever to that idea: they are simply required to give to the simile its proper form and order, or better to conceal the idea: the simile is therefore continued as far as necessary, according to its literal sense. Consider this well.

Guide for the Perplexed (c. 1190) - Introduction