Horse joke

There is a swift horse. The rider only needs to say "my mother" and the horse will run at full speed to reach its destination. If he wants to stop, he will shout "My Land" and the horse will stop. A businessman bought this horse, said "My mother" and the horse flew away (but there was no destination) ... Suddenly, the businessman saw a cliff in front of him, and he was so anxious that he forgot the formulas: "My God", "My father" and "My son" ... Finally, at the moment when he was about to rush out of the cliff, the businessman shouted "My land".