"as the Oracle at Delphi said to the Spartans"

 Ancient Delphi was the site of a prophetic Oracle known as the Pythia. The Greek God Apollo gave the female Pythia the power of prophecy, and her temple offered advice and guidance for many years, from the 8th century B.C. to 393 A.D., when the emperor Theodosius ordered the closure of all pagan temples.

A great many writers mention the oracles, including Plato, Aristotle, Thucydides, Sophocles, Xenophon, Euripides and Ovid.

Delphic advice was notoriously open to interpretation. Herodotus recounts that when Croesus of Lydia consulted the oracles before his war with Persia he was told that if he went to war he would 'destroy a mighty empire'. He took this to be an encouragement: in fact, the empire he destroyed was his own.

Attempts have been made to find  a scientific explanation for the oracles at Delphi. A common theory is that hallucinogenic gases from the Kerna spring were responsible for the Pythia's obscure messages; others think that a network of spies collected information for her.