There are problems that are solved not with more effort, but with a single idea that inverts everything. This is one of them.
The impossible race
Riddle statement
A sultan promises his inheritance to one of his two sons, but imposes a strange condition:
it will be won by the owner of the horse that arrives the latest in the neighboring city.
As soon as they hear the rule, the two princes stop moving. Neither wants their horse to arrive before the other's.
Time passes and, seeing that the race does not start, they consult a wise woman from the desert. She tells them a single sentence.
Immediately, the two mount up and leave at full speed.
What did she say to them?