Histories

Herodotus

Herodotus. Godley, Alfred Denis, translator. Cambridge, MA; London: Harvard University Press; William Heinemann, Ltd., 1920-1925 (printing).

and often, when they were in the act of charging the Persians, the horses would shy in fear if they heard the asses bray or would stand still with ears erect, never having heard a noise like it or seen a like creature.