From the most important monument of antiquity - the sanctuary of Apollo - Pythia (the High Priest of the god Apollo) gave its oracles in an enigmatic form, the interpretation of which was undertaken by the priests of the temple.
Pythia is not a specific fortune teller. It is more of a title given to the one who each time was chosen to be the chosen one of the god Apollo.
Pythia, the woman who was the mediator between the god and the believers, was not accidental. He must have been a hypersensitive creature, capable of falling into a state of occupant alienation, not only believing that he was communicating with God but also convincing others of it. Probably the first Pythians or a specific woman of Delphi had this gift, which created the first reputation of the oracle. After all, the selection of the Pythians from the priesthood should have been related to their faith and devotion to the worship of Apollo, so it was done only from the surrounding area.
Before the ordination Pythia was purified with water from the source of Castalia, as well as the temple, the priests, the staff of the sanctuary, the pilgrims. Castalia also gave her poetic / prophetic inspiration, but the pre-eminent prophetic source was Kassotis gushing into the sanctuary of the temple. Initially, Pythia used to officiate once a year, on the birthday of Apollo, on the 7th of the month of Vysos. Later, he served on the 7th of each month, except during the winter months when Apollo was absent in the Far North or in the Tempe Valley.