it is said that once sun was on earth, and caught horse to ride it. but it was unable to bear his weight, and therefore ox took the place of horse, and carried sun on its back. since that time horse is cursed in these words, because it could not carry sun's weight:

"from to-day thou shalt have a (certain) time of dying.

this is thy curse, that thou hast a (certain) time of dying.

and day and night shalt thou eat,

but the desire of thy heart shall not be at rest,

though thou grazest till morning and again until sunset.

behold, this is the judgment which i pass upon thee," said sun.

since that day horse's (certain) time of dying commenced.