Regum et imperatorum apophthegmata

Plutarch

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

Memnon, who was waging war against Alexander on the side of King Darius, [*](Circa 333 B.C.) when one of his mercenary soldiers said many libellous and indecent things of Alexander, struck the man with his spear, saying, I pay you to fight Alexander, not to malign him.