Bṛhad-āraṇyaka upaniṣad 1:1:2

The beginning of this verse is quite complex, so I'll break it down word by word. You'll realise why commentaries written by experts are indispensable! And why it is necessary to refer to more than one, to work out what is going on. At the same time, why should you depend on pre-digested, pre-interpreted texts alone? Learning Sanskrit  helps me interpret and choose the version best suited to my 'self'. Perhaps it will do the same for you...Below I give you four expert interpretations of the same sentence. 

The syntax is obscure and can be read in a variety of ways. This is one of the reasons that every school, every sect in Hinduism has been able to interpret in their own way and draw succour from the same scripture. For this particular verse, I 'vibe' best with S. Radhakrishan's translation.

अहर्वा अश्वं पुरस्तान्महिमान्वाजायत 

Ahar vā aśvam purastān mahimān vajāyata

अहः वा अश्वम्  पुरस्तात् महिमान् वाजयत  

अहः - day; neuter noun अहन्  

वा - indeed, verily; on its own, it stresses the word preceding; it could mean 'or' and if it appears twice in the sentence, it means 'either, or'. 

अश्वम् - horse; masc. noun. here in the accusative. Normally meaning 'to the horse' (horse को), the second case sometimes is used like the dative 'for the horse'   

पुरस्तात् - as an adverb, means firstly, initially; as an indeclinable it means in front of before; in or from the east, eastward. [Because in their world view, the East was always 'before' them, ahead of them]

महिमान् - a golden sacrificial cup that is placed before the horse in the aśvamedha ceremony

वाजयत - past tense of √वाजय 1A to worship; to race, hasten; to urge, incite, impel 

The interpretation of this sentence seems to hinge on how you translate 'वा' पुरस्तात् वाजय and which case function you take for the accusative in अश्वम् 

S. Radhakrishnan's translation:

The day verily arose for the horse, as the vessel called mahiman appeared in front (of the horse). [appeared is supplied by SR]

Patrick Olivelle: 

The day, clearly, was born afterwards to be the sacrificial cup placed in front of the horse.

Sri Aurobindo:

Day was the grandeur that was borne before the horse as he galloped. [galloped is supplied by SA]

Swami Madhavananda:

The (gold) vessel called Mahiman in front of the horse, which appeared about it (i.e. pointing it out) is the day. [appeared supplied by SM]

And now the rest of the verse from S. Radhakrishnan:

Its (the day's) source is in the eastern sea (तस्य पूर्वे समुद्रे योनिः) The night verily arose for the horse, as the vessel called mahiman appeared behind (the horse). Its source is in the western sea (तस्यापरे समुद्रे योनिः) These two (एतौ ) verily arose (संबभूवतुः) on the two sides (अभितः) of the horse as the two sacrificial vessels (महिमानौ). Becoming a steed (हयः) he carried (अवहत्)  the gods (देवान्); as a stallion (वाजी)  the gandharvas; as a runner (अर्वा)  the demons (असुरान्), as a horse (अश्व:), men (मनुष्यान्) . The sea indeed is his relative (बंधु:)*, the sea is his source (योनिः)

And Patrick Olivelle's translation:

The day, clearly, was born afterwards to be the sacrificial cup placed in front of the horse, and its womb is in the eastern sea.  The night was born afterwards to be the sacrificial cup placed behind the horse, and its womb is in the western sea. These two came into being to be the sacrificial cups placed in front of and behind the horse. It became a racer and carried the gods. It became a charger and carried the gandharvas. It became a course and carried the demons. It became a horse and carried the humans. The sea, indeed, is its counterpart; the sea is its womb.


*बंधु: is translated in different versions as relative, brother, counterpart.

A quick word about the numbering, for those who are not familiar with it. In 1.1.2, the first 1 refers to the chapter or अध्याय।The next 1 refers to the hymn or ब्राह्मण and last digit refers to the verse. This the, was the second verse of the first hymn of the first chapter of the Bṛhad-āraṇyaka upaniṣad.

The visual from google images is a coin minted during the Gupta period to commemorate the Aśvamedha performed by Samudragupta, (c.335-375 AD). On the left is the tethered horse, and on the right, the queen carrying the ritual equipment.