Pausanias, Description of Greece 7.22.2
The market-place of Pharai is of wide extent after the ancient fashion, and in the middle of it is an image of Hermes, made of stone and bearded. Standing right on the earth, it is of square shape, and of no great size. On it is an inscription, saying that it was dedicated by Simylos the Messenian. It is called Hermes Agoraios (of the Market), and by it is established an oracle. In front of the image is placed a hearth, which also is of stone, and to the hearth bronze lamps are fastened with lead. Coming at eventide, the inquirer of the God, having burnt incense upon the hearth, filled the lamps with oil and lighted them, puts on the altar on the right of the image a local coin, called a ‘copper,’ and asks in the ear of the God the particular question he wishes to put to him. After that he stops his ears and leaves the marketplace. On coming outside he takes his hands from his ears, and whatever utterance he hears he considers oracular