Apophthegmata Laconica

Plutarch

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

Archidamus, the son of Agesilaus, when Philip after the battle of Chaeroneia, wrote him a somewhat haughty letter, wrote in reply, If you should measure your own shadow, you would not find that it has become any greater than before you were victorious.