"They hold it unlawful to talk of anything which it is unlawful to do. The most disgraceful thing in the world, they think, is to tell a lie; the next worst, to owe a debt: because, among other reasons, the debtor is obliged to tell lies. If a Persian has the leprosy he is not allowed to enter into a city, or to have any dealings with the other Persians; he must, they say, have sinned against the sun. Foreigners attacked by this disorder, are forced to leave the country: even white pigeons are often driven away, as guilty of the same offence. They never defile a river with the secretions of their bodies, nor even wash their hands in one; nor will they allow others to do so, as they have a great reverence for rivers. There is another peculiarity, which the Persians themselves have never noticed, but which has not escaped my observation. Their names, which are expressive of some bodily or mental excellence, all end with the same letter---the letter which is called San by the Dorians, and Sigma by the Ionians. Any one who examines will find that the Persian names, one and all without exception, end with this letter." (Source: Encyclopedia of Ancient Persia)
Herodotus on Ancient Persia's Cultural Interactions with Foreign Nations
