What is your profound interpretation of the movie "Save My Sir"?

Andy was tied up and said he wanted to eat apples. As a result, there were no apples in the kidnapper's nest. I thought it was over, but I didn't expect the kidnapper to buy him an apple on his way back the next day. Perhaps for the kidnapper, this move was only because he was in a good mood, but for Hua Zai, he felt a little kindness in a heinous person. At the end of the film, Hua Zai went to the prison to give the kidnappers a basket of apples, probably to tell them that every kindness can be rewarded tenfold.