In Canto 29, Dante describes the origins of the Angelic Beings, as Beatrice can see in the Eternal Mind that the Pilgrim has some questions.
Firstly, the argument is that the Angels were created in order to reflect and “resplendor” the Divine Glory throughout all of Being and Existence (“Subsisto”), in their different natures. Therefore “new loves blossomed from the Eternal Love”.
Secondly, as for the “when”, Beatrice explains that the Angels, the Heavens and the Earthly were all created at the same time, like “three arrows from a three-stringed bow.” This threefold creation was “rayed into existence all at once, without beginning, with no interval.” And there was no “before” this, as time is not a part of Eternity.
Thirdly, the Angelic Beings/Forces were created in the Empyrean – and Dante describes how there are more of them than the doubling of the chessboard, meaning more than 18 billion billion.
A very interesting idea is how the angels are practicing their art “with such delight they take no time to pause, but whirl forever.” So even if there is no time or change, there is still movement and activity in the Empyrean. One way to ponder this is the billions of manifestations of love or knowledge every day in the Earthly Life, as actualizations of the Angelic Forces that are still timeless and unchangeable, but active and “whirling”.
So with this, Beatrice as theology has explained the “where and when and how” of the Angelic Beings, and the Canto ends with some incredible poetry about how the angelic nature is going “so far beyond the scale of mortal numbers, that there is no word or concept that can reach that far. [..]The primal Light shines down through all of them and penetrates them in as many ways as there are splendors with which It may mate.”
The final verses reflect the opening tercet in Paradiso once again – as the Pilgrim now can see “the breadth of Eternal Goodness that divides Itself into these countless mirrors that reflect Itself, remaining One, as It was always”. The Glory is penetrating and reflected in the whole of the Universe, in some parts less, and in some parts more.