Aswins (Sk.), or Aswinau, dual ; or again, Aswinî-Kumârau, are the most mysterious and occult deities of all; who have “puzzled the oldest commentators”. Literally, they are the “Horsemen”, the “divine charioteers”, as they ride in a golden car drawn by horses or birds or animals, and “are possessed of many forms”. They are two Vedic deities, the twin sons of the sun and the sky, which becomes the nymph Aswini. In mythological symbolism they are “the bright harbingers of Ushas, the dawn”, who are “ever young and handsome, bright, agile, swift as falcons”, who “prepare the way for the brilliant dawn to those who have patiently awaited through the night”. They are also called time “physicians of Swarga” (or Devachan), inasmuch as they heal every pain and suffering, and cure all diseases. Astronomically, they are asterisms. They were enthusiastically worshipped, as their epithets show. They are the “Ocean-born” (i.e., space born) or Abdhijau, “crowned with lotuses” or Pushhara-srajam, etc., etc. Yâska, the commentator in the Nirukta, thinks that “the Aswins represent the transition from darkness to light ”—cosmically, and we may add, metaphysically, also. But Muir and Goldstücker are inclined to see in them ancient “horsemen of great renown”, because, forsooth, of the legend “that the gods refused the Aswins admittance to a sacrifice on the ground that they had been on too familiar terms with men”. Just so, because as explained by the same Yâska “they are identified with heaven and earth”, only for quite a different reason. Truly they are like the Ribhus, “originally renowned mortals (but also non-renowned occasionally) who in the course of time are translated into the companionship of gods”; and they show a negative character, “the result of the- alliance of light with darkness”, simply because these twins are, in the esoteric philosophy, the Kumâra-Egos, the reincarnating “Principles” in this Manvantara.
Source: H.P.Blavatsky - The Theosophical Glossary