What revelation does the messenger make to Oedipus?

I'm thinking you are referring to the following,

"A man arrives from Corinth with the message that Oedipus's father has died. Oedipus, to the surprise of the messenger, is made ecstatic by this news, for it proves one half of the prophecy false, for now he can never kill his father. However, he still fears that he may somehow commit incest with his mother. The messenger, eager to ease Oedipus's mind, tells him not to worry, because Merope was not in fact his real mother."