What story does Jocasta tell to try to convince Oedipus that soothsayers are not necessarily right? Scene 2

Jocasta reveals that an oracle once came to Laius and told him that he would be killed by his son, though she too reiterates that Laius “was killed by foreign highway robbers / at a place where three roads meet” (715-6). She tells Oedipus that, three days after his birth, Laius pierced the ankles of the child and had him cast forth “upon a pathless hillside” (720). This news worries Oedipus, for some reason. He asks exactly where the crossroads was that Laius was killed – Jocasta tells him, and describes Laius. “I think I have / called curses on myself in ignorance”, says Oedipus (744-5), fearing he has killed his father. They send for the herdsman who escaped from the murder-scene at the crossroads.