Apophthegmata Laconica

Plutarch

Plutarch. Moralia, Vol. III. Babbitt, Frank Cole, translator. Cambridge, MA: Harvard University Press; London: William Heinemann Ltd., 1931 (printing).

Thorycion, arriving from Delphi and seeing in the Isthmus the forces of Philip, who had already gained possession of the narrow entrance, said, The Peloponnesus has poor gate-keepers in you, men of Corinth!