Arnobius

“ Piso believes that the Novensiles are nine gods, set up among the Sabines at Trebia. [5] Granius thinks that they are the Muses, agreeing with Ælius; Varro teaches that they are nine, [6] because, in doing anything, that number is always reputed most powerful and greatest; Cornificius, [7] that they watch over the renewing of things, [8] because, by their care, all things are afresh renewed in strength, and endure; Manilius, that they are the nine gods to whom alone Jupiter gave power to wield his thunder. ”