بما لا تحقق لمعناه حسّاً ولا عقلاً
With something whose intended content has no sensory or intellectual realization in that respect.
Some technical accounts of imaginative metaphor use this qualification. It does not say that claws never exist in animals. Rather, the special image of claws belonging to death does not exist externally as the rhetoric imagines it.
We must distinguish a familiar sensory property from its imagined attribution to an entity that lacks a body. The established concept of claws and the invented death-with-claws image are not identical objects of analysis.