What shocking revelation does the messenger reveal about Oedipus' family?

The revelation that Polybus was not Oedipus' real father is significant because it plays a crucial role in unraveling the tragic events of the play. The messenger confirms to Oedipus that he was adopted, which shifts Oedipus’ understanding of his identity. Throughout the story, Oedipus believes he is the son of Polybus, the king of Corinth, and this belief shapes his actions and decisions. When the messenger delivers the news that Polybus is not his biological father, it instigates a series of realizations for Oedipus regarding his true ancestry and the prophecies that have haunted him since his birth. This moment is pivotal as it sets Oedipus on a path to discover his true lineage, which is entwined with the tragic fate predicted by the oracle, further emphasizing the themes of fate versus free will and the quest for self-knowledge in the play.