theme of speech or speaking/persuasion in oedipus at colonus?

reading OAC- the speakers often refer to the act of speech itself, as prophecy, as persuasion, as falsehood etc.
I've looked cursorily for sources that may discuss this aspect of the play but can't find them.
am i just imagining it?
if not, how can I find a source (critical/literary) that discusses this motif?
or just share your opinion. thanks

yeah, well I wrote a great paper on it.... found some good sources.