Man's conscience is the oracle of God! [ Byron ]

Socrates
Whom, well inspired, the oracle pronounced,
Wisest of men. [ Milton ]

In the drawing of the heart is the oracle of fate. [ Friedrich Schiller ]

Each man is a hero and an oracle to somebody, and to that person whatever he says has an enhanced value. [ Emerson ]

If thou kiss Wisdom's cheek and make her thine, she will breathe into thy lips divinity, and thou, like Phoebus, shalt speak oracle. [ Decker ]

The god, O men, seems to me to be really wise; and by his oracle to mean this, that the wisdom of this world is foolishness and of none effect. [ Plato ]

Socrates was pronounced by the oracle of Delphos to be the wisest man in Greece, which he would turn from himself ironically, saying there could be nothing in him to verify the oracle, except this, that he was not wise and knew it, and others were not wise and knew it not. [ Bacon ]

Extreme old age is childhood; extreme wisdom is ignorance, for so it may be called, since the man whom the oracle pronounced the wisest of men professed that he knew nothing; yea, push a coward to the extreme and he will show courage; oppress a man to the last, and he will rise above oppression. [ J. Beaumont ]

Genius, without work, is certainly a dumb oracle; and it is unquestionably true that the men of the highest genius have invariably been found to be amongst the most plodding, hardworking, and intent men - their chief characteristic apparently consisting simply in their power of laboring more intensely and effectively than others. [ Samuel Smiles ]