والتشبيه باعتبار الغرض إما مقبول
Considered by its purpose, a simile may be acceptable.
An acceptable simile successfully serves its purpose: clarifying the subject's state, showing an unusual condition to be possible, intensifying a quality, or establishing a judgment through something the audience already recognizes.
An unacceptable simile fails to achieve the intended purpose. This judgment does not follow automatically from a simile's being familiar or remote. Either type may succeed or fail depending on how well it serves the context.