1. A student proposed hiding a poor man's shoes as a prank while he worked, but the professor suggested putting coins in the shoes instead to help the man.
2. They watched as the man discovered the coins in his shoes and was overcome with gratitude, believing the money would save his sick family from starvation.
3. The student was moved by witnessing the man's reaction and said the professor had taught him the lesson that giving to others is more rewarding than receiving.