Who was the Pythian Oracle of Delphi vs Tiresias in Oedipus Rex?

Sophocles' Oedipus Tyrannos (or Oedipus Rex) first came to the stage in Athens around 429-425 BCE. Although the play takes Thebes as its setting, the play has several references to the town of Delphi, which was the location of Apollo's famous oracle. The priestess whose mouth spoke for Apollo was called Pythia. Thus, the oracle at Delphi is sometimes called the Pythian oracle. Likewise, the town of Delphi is sometimes called Pytho. The oracle that Oedipus and his father Laius were trying to avoid was delivered by the Pythia.

As for Teiresias, he was a Theban prophet was also served Apollo. In Sophocles' play, Teiresias and Oedipus have an angry confrontation early in the play. In this scene, Oedipus eventually goads Teiresias into revealing that Oedipus was the one who killed his father and married his own mother.

Teiresias alludes to Oedipus' killing of his father Laius in the following quotation:

                    I say that you yourself
are the very man you’re looking for. (Johnston translation)

A few lines later, Teiresias hints at Oedipus' unwitting marriage to his own mother:

I say that with your dearest family,
unknown to you, you are living in disgrace. (Johnston translation)

Thus, both the Pythian oracle and the prophet Teiresias are representatives of the god Apollo.