Lucian of Samosata Rhetorum praeceptor 5

[5] Just to show you, I should like to tell you the tale of a Sidonian merchant's idea which disbelief made ineffectual and profitless to the man who heard it. Alexander was then ruler of the Persians, having deposed Darius after the battle of Arbela, and postmen had to run to every quarter of the realm carrying Alexander’s orders. The journey from Persia to Egypt was long, since one had to make a detour about the mountains, then to go through Babylonia to Arabia, and then to traverse a wide expanse of desert before reaching Egypt at last, after spending in this way, even if one travelled light, twenty very long days on the road. Well, this annoyed Alexander, because he had heard that the Egyptians were showing signs of disaffection, and he was unable to be expeditious in transmitting his decisions concerning them to his governors. At that juncture the Sidonian merchant said: “I give you my word, King Alexander, to show you a short route from Persia to Egypt. If a man went over these mountains—and he could do it in three days—he is in Egypt in no time!” And it was so! Alexander, however, put no faith in it, but thought that the merchant was a liar. ¹ So true is it that amazing promises seem untrustworthy to most people.