For those familiar with the Vedas, the Rg Veda contains one of the most famous yajnas, known as the Ashvamedha Yajna. While modern era scholars have argued that this is a literal sacrifice of a horse, even a casual read of this passage will reveal that this view simply is not logical. 
While the term Ashvamedha can literally mean the 'offering of the horse', it can also mean the 'essence of the horse'. In an age where the literal reading of texts is growing in popularity, all too often we lose the deep symbolic language and meaning of ancient teachings. The Nighantu and the Nirukta states that there are twenty-six synonyms for horse, indicating a deep and rich symbolic language structure; and of these numerous synonyms for horse, the one that is most applicable for our purposes is the term Ashva. As a term ashva has a strong association with the Ashvins, note that the Ashvins have horses to pull their car across the heavens, but what is more notable is that both nouns (Ashva and Ashvins) derive from the same verbal root as meaning ‘to pervade everything’. Not only do the Ashvins as deities pervade everything, their horses and the horse in general pervades everything as well, obviously indicating much more than a physical animal. In this initial examination, a picture is beginning to manifest that the ‘horse’ is an indicator of something much more then the literal horse.
As the divine physicians, the Ashvins are associated with prana or life-force energy. While the Vedas mentions that there are thousands of forms of Vayu (lord of air/prana), indicating there are thousands of forms of prana. The Ashvins are namely prana and apana from a yogic view, though one could say they would exert an influence over the other forms of prana as well. Likewise, there is support to see the Ashvins as associated with Pitta and Kapha from an Ayurvedic view. This is indicated by one Ashivin being associated with moisture, the other with light. This could also indicate Pitta as moisture and Kapha as moisture as both have a watery quality and would be requirements for vitality. The light aspect would be Pitta’s association with fire and Kaphas association with reflected light—the moon. The more subtle forms of this would be in the form of tejas (pitta) and ojas (kapha). From a yogic view, this would associate them with the Ida and Pingala nadi , and the horses being literal prana associated with the sushmna nadi, which would indicate the Ayurvedic vata and its subtle form of prana. This is supported more by the most subtle forms, namely deities—Vayu for Prana and vata. Agni (Yama) for tejas and pitta. Soma for ojas and Kapha.
This connection between the Devas and prana is further indicated in the Rg Veda which states:
Awaken the Ashvins who create union early in the morning, may they come and drink Soma.
-Rg Veda 1.22.1
The early morning for the yogi or yogini is the time of the ‘wind of Brahman’ and a period that spiritual seekers deeply connect with the cosmic prana, represented by the Ashwins and horse as prana. This time is roughly two and one-half hours prior to sunrise, as the wind of Brahman period ceases with the sunrise and a different group of deities are invoked. But the most interesting commentaries arise within the suktam itself.
But one must ask, 'what of the horse itself?' Clearly there are qualities that are given to the horse that are beyond the realm of the physical body. The suktam states that the horse is to be glorified whether first springing from the firmament or from the waters, and is described as having wings of a falcon and legs of deer (Rg Veda 1.22.7). Both these symbols are associated with prana within Hinduism and yoga. But this verse goes further equating the horse with the Devas themselves. As Rg Veda 1.22.7-2-5 states that the horse is one with Yama, Aditya and Trita. Some equate Trita as a vedic water deity, but commentators such as Sayana list Trita as a synonym for Vayu. Aditya is a sun deity. Yama in this case, according to Sayana, is a reference to Agni. One might argue over the changing meaning of Yama found within the Vedas, if the later period references to Yama within the Vedas are used this would be a reference to the 'original man'. But for our examination Yama and the associate with Agni does fit the model with Ayurveda and yoga. Interestingly, Yama and his sister Yami are equated with the Ida nadi and Pingala nadi within yoga. Additionally, the verse continues to equate the horse with Varuna, the Vedic deity of karma as well. Likewise, the horse is associated with the Vedic Deva Soma.
The idea of this being a literal horse is quickly dismissed as the origin of the horse is quite clear, as the sloka clearly states, ‘The Vasus created the horse from the sun…’ (Rg Veda 18.104.22.168). This clearly indicates the horse coming from soul or Brahman depending upon the philosophical system that is being applied to the Vedas. This idea is further expanded by the rik teaching that “…Indra first mounted him, the Gandharvas seized his reins…” (Rg Veda 1.22) indicating the unity of higher mind and sound joining the prana represented by the horse. The Gandharvas are known to have lived in the land of Gandhara which is the land of horses. This is a subtle reference to speech.
Within the Vedic ritual there is the yajamana, which is a pole that the sacrifice is tied to. This pole is equated with the spinal column according the yoga tradition, and in particular relates to the sushmna nadi in the astral body aligned with the location of the spinal column. Again this nadi is associated with prana and ether/air. Revealing that the sacrifice that is focused on is the energizing/balancing of the Ayurvedic doshas of Vata/Pitta/Kapha as well as their subtle aspects of Prana/Tejas/Ojas, as well as the energizing/balancing and focusing of the cosmic pranic forces into the physical body. As well as an offering of ones own vital air to Divinity.
It becomes apparent that the Ashvamedha yajna is filled with a deep and rich symbolism. Likewise, it becomes apparent that the literal 'horse sacrifice' is a somewhat limited view of the depth and richness of the Vedas, as well as missing numerous key points relative to the Devas and important Ayurvedic concepts. The deeper examination removes the Ashvamedha from some obscure ritual from a distance era into a yajana that has a great deal of relevance to the individual practitioners of yoga and Ayurveda. Not only teaching a deeper spiritual practice but providing practical insight into the forces that support health, wellness and spirituality.
It is an advanced and important yajana for the serious seeker of truth. It does require study with a teacher skilled and knowledgeable in the Vedas and requires a serious student with a developed skill set. For those that are ready, it is an important step in spiritual growth.
Copyright 20016. All Rights Reserved.
 Note: This article will not address the aspect of the Ashvamedha relative to history and Kings. As that is not the focus of this paper.
 Nadi literally means stream. Nadi's are often viewed as streams of energy or flows within the body or astral body.
Regference material used:
The Nighantu and Nirukta
Not specific books but teachings from David Frawley, personal conversations as well.