A king once entrusted his son to a teacher. One day he saw the teacher mounted on a horse and his son walking behind like an attendant.
The king found this extremely distasteful and quietly summonsed the teacher. The teacher said,
"Sir, in a few days he will be king. He will be looked upon by the creation as a sovereign. If today he does not walk and run how then will he know at that time how it feels for others to walk?"
"Therefor I have made him to run (behind me) so that one day he may remember it and show mercy to others."