What does Oedipus relate about his past to explain fear in

In Sophocles' play "Oedipus Rex", Oedipus explains his past in act 1 scene 1 to establish the basis for his fear. He begins by recounting a prophecy he received as a young man from the oracle at Delphi. The prophecy stated that he would kill his father and marry his mother. To escape this fate, Oedipus fled from his hometown of Corinth and ended up in Thebes.

There, he solved the riddle of the Sphinx and was proclaimed king. He also married Iocaste, the queen of Thebes, who was destined to be his mother. Oedipus remained ignorant of these facts until a plague struck Thebes. In an effort to uncover the cause of the plague, Oedipus consulted the seer Tiresias, who revealed the truth about his parentage.

Oedipus is then filled with horror and guilt and relates his past to explain his fear. He fears that he will be punished for the crimes he has unknowingly committed - patricide and incest - and he anticipates the imminent fulfillment of the prophecy that has haunted him since he was a young man.