(Clearwisdom.net) During the Spring and Autumn Period, General Wu Zixu from Wu (a kingdom in what is now China) was going to lead his soldiers to attack Zheng (another kingdom). Zheng Dinggong, the emperor of Zheng said, "Whoever can get Wu Zixu to take his soldiers back and not attack us, I will heavily reward him." However, nobody had a good idea.
On the fourth day's morning, a young fisherman came to Zheng Dinggong and told him, "I have an idea on how to get Wu Zixu to give up attacking Zheng." Once Zheng Dinggong heard this, he asked the fisherman right away, "How many soldiers and chariots do you need?" The fisherman shook his head and said, "I don't need any soldiers and chariots, or food, I only need my paddle and I can get tens of thousand soldiers from Wu to go back to Wu." The fisherman put the paddle underneath his arm and went to the barracks of Wu to find Wu Zixu.
While he was singing a song, he was tapping on the paddle, "Man from the reed, man from the reed; crossed a river, who's favor? On the precious sword was 7-star inscription; return it to you, take it in my hand. Today, you are so complacent, do you remember the fisherman?" Once Wu Zixu saw the paddle in fisherman's hand, he asked him immediately, "Young man, who are you?" The fisherman replied, "Have you seen the paddle in my hand? My father lived with this paddle. He saved you with this paddle!" Once Wu Zixu heard this he said, "I remember now! Before, when I fled from calamity, there was a fisherman who saved me. I was hoping to reward him! You are his son. What do you come here for?"
The fisherman said, "It's because your country is going to attack us. All of us fishermen were called. Our emperor Zheng Dinggong said, "If somebody could persuade General Wu to withdraw his soldiers and not attack Zheng, I will greatly reward him!" For the sake of my father who died, that once saved you, I hope that General Wu won't attack Zheng, so I could get the reward after I go back to Zheng." Wu Zixu said in a thankful tone, "Because your father saved me, I could be alive and so become a general. How I could forget his favor? I will definitely do you this favor!"
After Wu Zixu finished his words, he took all of his soldiers back to Wu. The fisherman was so happy, he told this good news to Zheng Dinggong. Right away, the whole country of Zheng treated this fisherman as their knight in shining armor and called him "fishing doctor." Zheng Dinggong rewarded him with a huge plot of land!
In order to pay back the fisherman's father who once saved him, Wu Zixu not only stopped attacking Zheng, but also helped the fisherman to be rewarded. This is called, "Be grateful and seek to requite." This is a traditional good virtue of the Chinese nation. Later, we used the idiom, "Be grateful and seek to requite" to express that we have to show gratitude for someone else's favor and hope to return the favor someday.