Before Lu Dongbin became an immortal, he was a scholar. Among his friends was a fellow countryman named Gou Yao. Gou Yao's parents are both dead and his family is poor, but he is a loyal and sincere gentleman, and he is very diligent in studying. Lu Dongbin admired him very much, swore sworn brothers with him as Jinlan, and invited him to live in his home. He hoped that he could study hard and prosper in the future. One day, a guest named Lin came to Lu Dongbin's house. Seeing that Gou Yao was a talented person and studied hard, he told Lu Dongbin that he wanted to betroth his sister to Gou Yao. Lu Dongbin was deeply afraid that Gou Yao's greed for bed pleasure would ruin his bright future, so he quickly excused himself. Unexpectedly, Gou Yao himself heard that Miss Lin was beautiful and insisted on agreeing to the marriage. Lu Dongbin thought for a long time and agreed. He said to Gou Yao: "Since my brother has made up his mind, I will not stop him. However, after we get married, I will sleep with the bride for three nights first." Gou Yao was shocked when he heard this. How can you not bow your head when you are living under someone else's roof? Besides, all the expenses for the wedding have to be relied on by the Lu family, so who would let yourself be destitute? After thinking about it, he gritted his teeth and agreed. On Gou Yao's wedding day, Lu Dongbin was beaming with joy and ran back and forth to organize everything. But Gou Yao had no face to see anyone, so he simply hid aside. In the evening, after seeing off the guests, Lu Dongbin entered the bridal chamber. I saw the bride's head covered with red gauze, sitting on the bed. Lu Dongbin did not lift the red hijab, nor spoke. He just sat under the lamp and immersed himself in reading. Ms. Lin waited until midnight, but her husband still didn't go to bed, so she had to go to bed with her clothes on. When I woke up in the morning, my husband was already gone. It was like this for three nights in a row, but Ms. Lin was so miserable that she said it later. After three days, she finally got through it. When she entered the bridal chamber, she saw that the lady was crying sadly. She lowered her head and cried and said, "Why have you been doing this for three nights in a row?" You don't even go to bed to sleep together, you just read by the lamp, come in the dark and leave in the morning?" Gou Yao was dumbfounded by this question. The bride raised her head and looked, and she was even more surprised: Why was her husband a different person? It took a long time for the couple to suddenly realize. Gou Yao stamped his feet, looked up to the sky and laughed: "It turns out that my brother was afraid that I would be greedy for pleasure and forget to study, so he used this method to motivate me!" Miss Lin was also happy in her heart and was full of respect for Lu Dongbin. The couple both said: Brother Lu must repay this kindness in the future. A few years later, Gou Yao was indeed named on the gold medal list and became a high official. The couple bid farewell to Lu Dongbin's family in tears and went to take office. Eight years passed in the blink of an eye. In the summer of this year, the Lu family accidentally caught fire, and so much of the family wealth was reduced to ashes. Lu Dongbin and his wife had no choice but to live in a hut made of broken bricks and tiles. Needless to say, life was difficult enough. Lu Dongbin had no choice but to go out to find Gou Yao for help. After going through a lot of hardships along the way, I finally found Gou Yao Mansion. Gou Yao was very sympathetic to Lu Dongbin's house that suffered a fire, and received him warmly, but did not mention helping him. Lu Dongbin stayed there for several months without getting any money. Lu Dongbin looked up to the sky and sighed: "Human feelings are as thin as paper, and their faces change as soon as they are broad, and they are eloquent all over the world!" In a fit of anger, he left without saying goodbye. When he returned to his hometown, Lu Dongbin saw that his dilapidated thatched hut had been replaced by a new tile-roofed house. He was very surprised: How could he carry out large-scale construction projects when he was far away from home with a young son and a weak wife? When he approached the house, he was even more shocked that his three souls walked away for two seconds. Po: There were white papers posted on both sides of the door. Someone died in the family? He hurriedly entered the house and saw a coffin parked in the house. His wife was wrapped in sackcloth and mourning, and was crying loudly. Lu Dongbin was stunned for a long time: Who is she wearing mourning for? She called out softly: "Madam." The lady looked back, terrified, and shouted tremblingly: "You, are you a human or a ghost?" Lu Dongbin was even more surprised: "Madam. Why do you say this? I'm back fine, how can I be a ghost?" The lady looked at it for a long time before she dared to believe that Lu Dongbin was really back and said, "Oh! It really scared me to death! Could this be a dream?" It turned out that not long after Lu Dongbin left home, a group of people came to help him build a house. After building the house, they left. At noon the day before yesterday, another group of people brought a coffin, saying that Lu Dongbin died of illness at Gou Yao's house. When the wife heard this, the sky fell and the earth fell, and she cried to death. I was crying today, but I didn’t expect Lu Dongbin to come back. Lu Dongbin understood in his heart: it was all Gou Yao's trick. He picked up a sharp ax and chopped the coffin hard. With a "click", the coffin split open, and it was filled with gold and silver treasures, as well as a letter. Lu Dongbin opened the letter and read: "Gou Yao is not a heartless man. He helped the gold and silver family build a house on the road. You let my wife guard the empty house, and I will make your wife cry heartbroken." Lu Dongbin woke up from a dream and smiled bitterly: "My dear brother, what are you doing? Help, it’s so hard to help me!” From then on, the Lu and Gou families became more affectionate. This is the common saying that "Gou Yao and Lu Dongbin don't know a good heart." Because "Gou Yao" and "dog bite" have the same pronunciation, from time to time it became "Gou Yao Lu Dongbin doesn't know a good heart."