In antiquity Voces Magicae (magical words) or words of power were very popular in the magical practices.
Some of the oldest Voces Magicae (that are still known today) are the words of the Ephesian formula. Also called the Ephesian grammata and the Ephesian letters (and often confused with the writings of Paulus in the bible against the cult of Ephesus- these are named Ephesian letters, too).
The Ephesian formula are six words:
Askion, Kataskion, Lix, Tetrax, Damnameneus, Aisia (with variations of Aision instead of Aisia or Askei and Kataskei instead of Askion Kataskion).
These magical words appeared the first time in a inscription of the 5th century before Christ (a curse in which Hekate and Persephone were named). The formula was very popular in Ephesos and were used there as words of power. It is believed that they were inscribed on the Statue of Artemis Ephesia in her temple. Hekate had a temple in Ephesos, too. And a theory of scholars is, that Kybele or Hekate were the original Goddess that was honoured in the great temple of Ephesos until this Goddess was subsumed by Artemis during Hellenisation of Asia Minor (what happened to many local Goddesses). In late antiquity the Artemis of Ephesos and Hekate got syncretisised with each other and Ephesos was a centre of occultism and magic in this time period.
The Poet Anaxilas wrote in the fifth century before Christ that the Ephesian grammata were worn in cloth bags (similar like Mojo Bags). These bags were designed to bring great strength to the person that wore such a talisman or they were designed to protect fresh married couples.
In general the Ephesian formula was used in antiquity to give protection, as apotropaic spell (to avert evil), to get luck and good influences. They appear often in the magical inscriptions and spells- for example in the Greek Magical Papyry or in the Curse Tablets (which were not just used for curses only- but for other goals, too).
In the Greek Magical Papyri there is a spell that addresses Hekate-Ereschkigal- the first two words of the Ephesian formula are used in this spell together with other Voces Magicae (Askei Kataskei Eron Oreon Ior Mega Samnier Baui Phorbantia Semne). It was a spell for protection.
The word Damnameneia appears in the Greek Magical Papyri in a spell that addresses Hekate-Brimo. And in one of the great invocations of Hekate in these Papyri the word is used together with other Voces Magicae on her sceptre.
Plutarch wrote that Magicians told people that were possessed by Daimons that they should speak the 6 Ephesian letters over and over (I think as kind of exorcism).
The christian writer Clemenz of Alexandria translated the words in that way:
Askion is the darkness, Kataskion it the light, Lix is the earth, Tetrax is the year, Dammnameneus is the Sun and Aision the world. They symbolise the order of the world. Darkness to light, sun to the year, the earth to all kinds of creation in nature.
For me the six words are like a creation myth condensed to a magical formula.
First was the darkness, from darkness was born the light. The earth, the seasons and cycles and the order of the world.
For me personal the Ephesian letters are words of power in general, they can be used in a universal way. The longer formula from the Greek Magical Papyri feels more like it is more designed for protection, banishing of evil and other apotropaic uses.
And I use the longer formula more for this before and after rites to banish and clean the space (I have written a modern adaption of the spell for this use- it will appear in the Hekatean Prayer book- hopefully).
I use the six words from the Ephesian formula….
as a kind of Mantra in meditations,
I use them to create sacred space and a sphere of protection around me,
I use them to raise power/energy,
to charge amulets, talismans, tools, etc. with power,
I speak them over objects that I want to bless and consecrate,
I write them on paper an put them in Mojo Bags, amulets and talismans, use them on my cult statues and on other cultic or magical objects,
and I use them in invocations and evocations of Hekate and repeat them in these practices to strengthen the connection to her.