Oedipus sends Creon to Delphi to consult the oracle, or priestess, there, about the cause of the plague in Thebes. Creon reports that the gods have caused this plague in response to the murder of Laius, the previous king of Thebes, and they demand that the murderer ("the pollution of this land") be killed or exiled. Once this task is completed, the plague will be lifted.
Confident that he can save Thebes once again, Oedipus vows to discover the identity of the murderer, even if he is in his own house. He actually curses the murderer and promises to exile him once his identity is known. Ironically, Oedipus has cursed himself because he is the man who killed Laius, fulfilling part of the prophecy that he would kill his father and marry his mother.
Oedipus asks the oracle, Tiresias, who killed the king. He tells him that he knows the truth but wishes he didn't. Oedipus continues to ask but is met with no answers until he accuses Tiresias of being the murderer. The oracle tells Oedipus that he was the one who murdered the king. He continues that the murder is both brother and father to his children, and both son and husband to his mother.
The message is based on the plague within the city and how they must get rid of it, or else Apollo will be angry. Unbeknownst to Oedipus, he is the cause. He does everything and anything in order to find the murdered, when it is in fact he himself. Not only that, Oedipus is shown to lay false accusations on others once they tell him he is the murderer of his father and the husband of his mother. Finding out the answer to this drives him to his downfall at last.
Temple of Apollo: (Greek mythology) the oracle at Delphi where a priestess supposedly delivered messages from Apollo to those who sought advice; the messages were usually obscure or ambiguous.
Oracles In order to understand the will of the gods, the Greeks consulted oracles. These were places holy to a specific deity (often Apollo); humans could pose questions and the god would answer through a chosen intermediary. The most important oracle in the Greek world was Apollo’s temple at Delphi (also called Pytho, because legend said that it was founded when Apollo killed the previous resident, a giant snake, or python.). Here, Apollo answered questions through his priestess, the Pythia, who entered an ecstatic state and babbled out responses, which were in turn interpreted and delivered in verse by the priests. It was customary for kings and cities to consult the oracle of Delphi before making any big decision
The most important god for the Oedipus Rex is Apollo, whose oracle at Delphi gives the important prophecies to Oedipus and Creon (Laius was traveling to this oracle when he was killed). Apollo’s knowledge is absolute— if Apollo says something will happen, it will happen. His prophecies in this play, however, are not warnings: He does not tell Laius not to have children, merely that his child will kill him. He does not tell Oedipus to kill his father, but that he will kill his father. When Oedipus sends Creon to find out how to end the plague, Apollo tells them to drive the murderer of Laius out of Thebes, but this is not an instruction so much as a simple answer.