A shared or homonymous expression may have more than one separately recognized sense. An indicator can select which of those senses a speaker intends without necessarily making that use figurative.
“ʿAyn” can denote an eye, a spring, or another established sense. A construction such as “ʿaynu l-māʾ” selects a water spring. The need for such an indicator does not by itself dissolve the lexical assignment.
It is important to distinguish a selector among established senses from an indicator supporting a figurative transfer. The former resolves ambiguity; the latter participates in a different rhetorical operation.