What does the chorus seem to celebrate prematurely in fourth choral ode?

In Sophocles' play "Oedipus Rex," the fourth choral ode does not celebrate anything prematurely but instead contemplates the reversal of Oedipus' fate.

The chorus wonders if Oedipus' encounter with the Sphinx, during which he showed great intellect and wisdom, signifies a higher level of fate or if his suffering is a punishment for some transgression. They reflect on the unpredictability of fate and remind the audience of how quickly fortune can change for humans, cautioning against hubris.