In Oedipus Rex, nature is used as a pathetic fallacy or an objective correlative. In other words, the external plague in nature (disease, starvation) is symbolic of the internal corrupt nature of royal family.
The play begins with children suffering from the plague. Notice, the priest connects the suffering with a crime within a house:
Armed with his blazing torch the God of Plague
Hath swooped upon our city emptying
The house of Cadmus, and the murky realm
Of Pluto is full fed with groans and tears.
"Land" is mentioned 25 times in the play. The priest goes on to say:
This land, as now thou reignest, better sure
To rule a peopled than a desert realm.
Nor battlements nor galleys aught avail,
If men to man and guards to guard them tail.
The Chorus calls upon the gods (Zeus) to defend them from the disease of the land:
fell pollution that infests the land,
And no more harbor an inveterate sore.
If in the days of old when we nigh had perished, ye draveOedipus, ironically, looks to the land for the murderer instead of within himself. So, suffering in nature is symbolically juxtaposed to inward suffering and blindness. So says Oedipus:
From our land the fiery plague, be near us now and defend us!
But if an alien from a foreign land
Be known to any as the murderer,
Let him who knows speak out, and he shall have
Due recompense from me and thanks to boot.
But if ye still keep silence, if through fear
For self or friends ye disregard my hest,
Hear what I then resolve; I lay my ban
On the assassin whosoe'er he be.
Let no man in this land, whereof I hold
The sovereign rule, harbor or speak to him;
Give him no part in prayer or sacrifice
Or lustral rites, but hound him from your homes.