- Aspe-siha was the name of the favourite horse of King Vishtaspa, the patron king of prophet Zarathushtra. Literally the word aspe-siha means “a black horse”. The horse has become famous in Zoroastrian religious lore, since events in the life of prophet Zarathushtra are closely connected to this horse.
- It is stated that the four legs of this horse got embedded in its stomach and none in the kingdom was able to heal the horse from this condition. Finally prophet Zarathushtra, who was wrongly imprisoned by the king at that time, offered to heal the horse with the power of the prayers of Mazdayasni religion, thus proving his credential as a true prophet of Ahura Mazda. This incidence not only proved his innocence but also sealed his place as the true prophet of Ahura Mazda.
- This story is also allegorically explained in another way. Aspe-siha or black horse is considered symbolic of darkening of the mind of the king against the prophet and his religion by his detractors. The healing of the horse by the power of prayers is symbolic of clearing of the mind of the king from negative thoughts by the power of the Mazdayasni religion.