Full Idea
'Mentioning', or 'referring', is not something an expression does; it is something that someone can use an expression to do.
Gist of Idea
Expressions don't refer; people use expressions to refer
Source
Peter F. Strawson (On Referring [1950], §2)
Book Reference
'The Theory of Meaning', ed/tr. Parkinson,G.H.R. [OUP 1978], p.68
A Reaction
That can't be whole story, because I might make a mistake when referring, so that I used the expression to refer to x, but unfortunately the words themselves referred to y. The power of language exceeds the intentions of speakers.