An Historical Summary of Angelic Hierarchies from Part VII: The “Seven” Thrones in In Operibus Sigillo Dei Aemeth by David Richard Jones.

“As we have noted, these terms came with a metaphysical connotation from a prior sectarian Hebrew apocalyptic context. It is also possible that these terms had similar meaning in the context of the Middle Platonic cosmology and theurgy that was familiar to Paul’s Hellenistic audience, and about the development of which we unfortunately know little, but which was to come to fruition in the Chaldean Oracles and the works of Iamblichus and Proclus.” [via]