Majaz is not permission to assign words arbitrary unrelated meanings. Without a meaningful relation between primary and secondary senses, interpretation would become unreliable.
«لا بد لاستعمال اللفظ في غير ما وضع له من مناسبة»
A connection is required when using a word beyond the meaning for which it was originally assigned.
«كالأسد للرجل الشجاع»
As in using “lion” for a courageous person.
Asad denotes a lion literally and may describe a brave person because both share courage. The link is resemblance. Without a suitable relation and indication, the word cannot simply denote an unrelated thing.