Princess Wencheng, 16 years old, sensible, simple and generous, volunteered to be the wife of 24-year-old Songzan Gambu. According to legend, Lu Dongzan led a delegation to propose to Chang 'an, Tang Dou with 50 million taels of gold and a lot of jewels. Unexpectedly, Tianzhu, Dashi, Zhong Gesar and Wang Ting also sent messengers to propose marriage, hoping to welcome the virtuous Princess Wencheng back to be his concubine. Therefore, both Emperor Taizong and Li Shimin were embarrassed. In order to be fair and reasonable, he decided to let the marriage envoys compete for wisdom. Whoever wins can welcome the princess. This is the "six great marriage envoys" in history (also known as "six difficult marriage envoys" and "five marriage envoys"). The murals depicting this story have been well preserved in Jokhang Temple and Potala Palace in Lhasa. The first attempt: satin wears a zigzag pearl, that is, a soft satin (Han Yu) passes through the zigzag hole of the pearl. At the beginning of the game, due to the powerful influence of Tubo diplomats, I took it first and racked my brains, but I didn't get through several times. The clever Lu Dongzan sat under a big tree and thought about it. He happened to find a big ant, so he found a silk thread, tied one end of the silk thread around the ant's waist, and sewed the other end on the satin. Put honey at one end of the serrated hole and ants at the other end. When ants smell the fragrance of honey, with the help of Lu Dongzan's blowing force, they slowly climb out from the other side along the winding hole with silk thread, and the satin also passes through the winding pearl with the silk thread. The second test: identify the mother-child relationship between one hundred mares and one hundred foals. The game started, but I saw the wedding envoys take turns to identify each other. Some are distinguished by their coat color, some by their age, and some by their height. However, they are all wrong. Finally, it was Lu Dongzan's turn to be guided by the groom. He kept all the mares and foals separately, and only fed the foals without drinking water for a day. The next day, these foals were publicly released into the herd. They are reluctant to drink, and soon they all find their mothers to nurse, so it is easy to determine the relationship between mother and child. Then, Li Shimin, Emperor Taizong, gave a question to identify the mother-child relationship between 100 chickens and 100 hens. This incident stumped other wedding envoys again, and no one could identify it clearly. Lu Dongzan drove Jishan to the square and sprinkled a lot of vegetables. As soon as the hen saw the food, she called the chickens to eat, but most of them ran to their mother's neck and pecked. But there are still some naughty chicks who don't listen to the call and run around for food, so Lu Dongzan learned the kite's cry "Qu Jiu-Er-Qu Jiu-Er-". When the chick heard this, she believed it and quickly hid under her mother's wings. The relationship between the hen and the chick was confirmed again. The third test: it is stipulated that 100 suitors should drink 100 altar wine, eat 100 sheep and knead the sheepskin in one day. At the beginning of the game, other messengers and followers slaughtered the sheep in a hurry, and the ground was covered with fur and blood; Then drink in a big bowl and eat meat. When the meat is not finished, people are as drunk as a fiddler and can't afford to rub the skin. Lu Dongzan lined up the hundred knights who followed him to kill sheep, sipped wine in order, ate meat in small pieces, rubbed the skin while eating, and ate and drank. In less than a day, the envoys of Tubo finished drinking, eating meat and rubbing their skins. The fourth test: The Emperor of the Tang Dynasty gave the envoy a hundred pieces of pine, so that Guelton Zanyusong could distinguish its roots and buds. Gail then had all the wood transported to the river and thrown into the water. The roots of the wood are slightly heavier and sink into the water, while the tops of the trees are lighter but float on the water. The roots of wood are obvious. The fifth test: Don't get lost in and out of the Palace at night (it is said that you can still recognize the door in Vientiane Gate in Shi Jing). One night, a big drum suddenly sounded in the palace, and the emperor called messengers from all walks of life to the palace to discuss things. Lu Dongzan thought that he had just arrived in Chang 'an and was not familiar with the road. In order not to get lost, he marked the key road sections with the word "Tian" (or colored it). When they arrived at the palace, the emperor told them to go back immediately to see who wouldn't take the wrong way back to their residence. As a result, Lu Dongzan won again with his own marks made in advance. The sixth test: identify the princess. On this day, Tang Taizong, Li Shimin and other ministers came to the front of the temple and took the exam in person. But I saw 300 (or 500 or 2500) ladies-in-waiting dressed in gorgeous clothes, lined up from the palace in two teams in turn, just like 300 immortals floating through the air, light, chic and handsome, dazzling. None of the other messengers knew, and they didn't know which one was Princess Wencheng. Only Lu Dongzan knows her physical characteristics, because she was instructed by the Han grandmother who served the princess in advance: elegant posture, fair complexion, bright eyes, firm and gentle personality, dice pattern on her right cheek, lotus pattern on her left cheek, Huang Dan circle on her forehead (also known as red mole), and white and delicate teeth. After repeated identification, Lu Dongzan finally recognized the sixth princess on the left.