Strabo Geography 9.3.5

[5] They say that the seat of the oracle is a cave that is hollowed out deep down in the earth, with a rather narrow mouth, from which arises breath that inspires a divine frenzy; and that over the mouth is placed a high tripod, mounting which the Pythian priestess receives the breath and then utters oracles in both verse and prose, though the latter too are put into verse by poets who are in the service of the temple. They say that the first to become Pythian priestess was Phemonoe; and that both the prophetess and the city were so called ¹ from the word pythésthai,” ² though the first syllable was lengthened, as in athanatos, akamatos, and diakonos. ³ Now the following is the idea which leads to the founding of cities and to the holding of common sanctuaries in high esteem: men came together by cities and by tribes, because they naturally tend to hold things in common, and at the same time because of their need of one another; and they met at the sacred places that were common to them for the same reasons, holding festivals and general assemblies; for everything of this kind tends to friendship, beginning with eating at the same table, drinking libations together, and lodging under the same roof; and the greater the number of the sojourners and the greater the number of the places whence they came, the greater was thought to be the use of their coming together.

[5] The place where the oracle is delivered, is said to be a deep hollow cavern, the entrance to which is not very wide. From it rises up an exhalation which inspires a divine frenzy: over the mouth is placed a lofty tripod on which the Pythian priestess ascends to receive the exhalation, after which she gives the prophetic response in verse or prose. The prose is adapted to measure by poets who are in the service of the temple. Phemonoë is said to have been the first Pythian prophetess, and both the prophetess and the city obtained their appellation from the word Pythesthai, to inquire, ( πυθέσθαι). The first syllable was lengthened, as in the words ἀθάνατος ἀκάματος διάκονος.

¹ [The establishment of cities, and the honour paid to common temples, are due to the same feelings and causes. Men were collected together into cities and nations, from a natural disposition to society, and for the purpose of mutual assistance. Hence common temples were resorted to, festivals celebrated, and meetings held of the general body of the people. For friendship commences from and is promoted by attending the same feasts, uniting in the same worship, and dwelling under the same roof. The advantages derived from these meetings were naturally estimated from the number of persons who attended them, as also from the number of places from whence they came.]