In Ferdowsi’s Shahnameh, finished around 1010, six Zoroastrian priests test Zal’s wits in front of King Manuchehr while Zal is asking to marry Rudaba. This is one of their riddles, and Zal gets it.
Two fast, noble horses are racing, one like a black sea and the other shining like white crystal. They run as hard as they can, and neither ever catches the other. What are they?
Give me a hintThe hint
One arrives just as the other leaves.