Extended data:
Gratitude: From Schon. Qin Mugong tasted the death of his war horse and demanded it. When he saw people killing his horse, he only ate its meat. Mu Gong said, "It's my good horse." Everyone is afraid. Mu Gong said: "I heard that people who eat horse meat and don't drink kill people." Instant wine. Those who killed the horse all went away in shame. Three years later, he attacked Qin Mugong and surrounded it. People who used to eat horses said, "You can die to repay the kindness of eating horses." After the siege, Mu was able to solve the problem, win the gold and get the benefits of the people. -"Historical Records" Qin Benji fifth
Qin Mugong once went to the palace and lost his good horse. He went out to look for it himself and saw that someone had killed his horse and were eating horse meat together. Qin Mugong said to them, "This is my horse." These people all stood up in fear. Qin Mugong said: "I heard that people who eat good horse meat and don't drink will die." So I gave them drinks. All the people who killed the horse left in shame.
Three years later, the State of Jin attacked Qin Mugong and surrounded Qin Mugong. People who used to kill horses and eat meat said to each other, "It's time for us to repay Mu Gong for eating horse meat and drinking good wine." So he defeated the besieged army, and Mu Gong finally solved this difficulty, defeated the State of Jin and brought Jin back.
How good is it? From "Zuo Zhuan Gong Xuan Two Years": "I know what I did, and I will change it." He lowered his head and said, "Who is wrong? It's hard to change after that.
References:
Baidu Encyclopedia-Gratitude and Kindness.