Oedipus Rex reveals the prophecy which caused him to leave Corinth (791-93): "that I was fated to lie with my mother," "and show to daylight an accursed breed" "which men would not endure, and I was doomed" "to be murderer of the father that begot me." The implication of Laius's oracle is ambiguous. One interpretation considers that the presentation of Laius's oracle in this play differs from that found in Aeschylus's Oedipus trilogy produced in 467 BC. Helaine Smith argues: Sophocles had the option of making the oracle to Laius conditional ("if" Laius has a son, that son will kill him) or
Oedipus Rex Polybus then adopted. The baby, he says, was given to him by another shepherd from the Laius household, who had been told to get rid of the child. Oedipus asks the chorus if anyone knows who this man was, or where he might be now. They respond that he is the "same shepherd" who was witness to the murder of Laius, and whom Oedipus had already sent for. Jocasta, who has by now realized the truth, desperately begs Oedipus to stop asking questions, but he refuses and Jocasta runs into the palace. When the shepherd arrives Oedipus questions him, but