vii. 5. 25.

He who knows the head of the sacrificial horse becomes possessed of a head and fit for sacrifice. The head of the sacrificial horse is the dawn, the eye the sun, the breath the wind, the ear the moon, the feet the quarters, the ribs the intermediate quarters, the winking the day and night, the joints the half-months, the joinings the months, the limbs the seasons, the trunk the year, the hair the rays (of the gun), the form the Naksatras, the bones the stars, the flesh the mist, the hair the plants, the tail hairs the trees, the mouth Agni, the open (mouth) Vaiçvanara [1], the belly the sea, the anus the atmosphere, the testicles the sky and the earth, the membrum virile, the pressing-stone, the seed the Soma. When it chews, there is lightning; when it moves about, there is thundering; when it makes water, there is rain; its speech is speech. The Mahiman (cup) indeed is born before the birth of the horse as the day. The Mahiman (cup) is born after it as the night. These two Mahiman (cups) surround on either side the horse. As Haya (steed) it carried the gods, as Arvan (courser) the Asuras, as Vajin (racer) the Gandharvas, as Açva (horse) men. The birthplace of the horse, indeed, is the sea, its kindred is the sea.