what connection does the messanger have with oedipus's past, and what has he come to tell oedipus?

The messenger came to tell Oedipus that his father, Polybus, has died of natural causes, but Oedipus still worries over the part of the prophecy that says he will sleep with his mother. The messenger (shepherd), being the one who gave him to Polybus and Merope then tells him he has nothing to wotty about because they were not his natural parents........ and this is where it all really starts to fly!