The Analects has a saying: Years are cold, and then after knowing the pine cypress, they wither. Pine cypress refers to the two kinds of trees, pine trees and cypress trees, because they are tall and tall, so in ancient times they symbolized high purity, firmness and pride, implying that a gentleman stood tall in the sky. Later, in order to commemorate the ancestors, people planted two kinds of trees in front of the tombs of the ancestors, which means that they were noble and clean before they died, and they will also shade their descendants after death, so they can often see the two rows of tall pines in front of a lonely small dirt bag.
However, if someone is more careful, they will find that in those film and television dramas with a relatively good degree of historical restoration, the emperor went to worship the ancestors, and in front of the tombs of previous generations of emperors, he never saw cypress trees, only pine trees. So the author went to look for historical materials, found that the emperor's mausoleum is not planted with cypress trees, in the folk cypress symbolizes high purity, the people will plant tall cypress trees in front of the ancestral tombs, why is the emperor's mausoleum not planted cypress trees?
On this issue, there is a clear record in the Book of Rites, which has a saying that "His Holiness is high and has many trees, and the lowly ones seal and few trees." The tomb of the Son of Heaven is three blades high, and the tree is pine; the princes are half-wise, and the tree is cypress; the doctor is eight feet, and the tree is luan; the soldier is four feet, and the tree is locust; the people have no grave, and the tree is willow." In the Book of Rites, people are divided into three, six, and nine grades, with the Son of Heaven as the highest, the princes second, the scholars and masters again, and the commoners as the lightest.
Therefore, the trees in front of the tomb also match their identity, and the status of the Son of Heaven is noble, and the trees in front of the mausoleum are tall and numerous, and pine trees are planted. The princes were a little lighter than the emperors, so cypress trees were planted in front of the tombs, locust trees were planted in front of the tombs of the scholars, and the common people had no graves and planted poplar trees and willow trees. Regardless of the kind of tree, the difference is that it is tall and short, but it is very tall, so whether the status is noble or not, it can be reflected in the tree in front of the grave, but regardless of the various identities, after death, the tree that symbolizes the purity and steadfastness should be planted in front of the grave.

From this passage of the Book of Rites, it can be seen that the reason why the Tianzi Mausoleum does not plant cypress trees, so when did the Tianzi Mausoleum not plant cypress trees in front of it? First of all, we must start from the "Book of Rites", which was written by Dai Sheng during the Western Han Dynasty, which is a very important classic in ancient China and an indispensable subject in the later examination of the imperial examination system. It can be seen from the name of the Book of Rites that it is written about the ritual system of the pre-Qin period and embodies the pre-Qin Confucian thought.
From this point of view, the book of Rites is the mainstream idea or the pre-Qin period, mainly Based on Confucius thought, so it is inferred that the ritual system recorded in it should be handed down from the Zhou Dynasty, because the Chinese ritual music system was perfected in the Zhou Dynasty.
A review of the texts found that the western Zhou Tianzi was buried in the form of a tomb, without sealing the soil and without planting any trees in front of the mausoleum. Since then, the ritual system of planting pine trees without cypress trees in front of the tombs of later emperors did not originate in the Western Zhou Dynasty, so from another aspect, the Book of Rites records the pre-Qin Confucian thought on the ritual system, and since it is not from the Ritual System of the Zhou Dynasty, it is related to Confucianism.
Through historical materials, it was found that Confucius loved trees all his life, especially trees with tall ratios such as pine cypresses, which symbolized the purity of a gentleman and the supremacy of heaven and earth, and there are also many records of pines from other trees in the Analects. After the death of Confucius, his disciples in order to commemorate him, they planted his favorite pine cypress tree in front of his tomb, because Confucius's disciples were all over the country, so soon Confucius's tomb in front of the pine cypress forest, in addition to pine cypress, there are other varieties of trees, later generations called this forest "Kong Forest".
From this point of view, planting trees in front of the tomb to commemorate the origin of the ancestors is not the Zhou Dynasty ritual system, but because of the Kong sage.
So what is the reason for the development of this kind of Heavenly Son's mausoleum in the future generations, not planting pine trees but only pine trees? The Book of Rites was compiled during the period of Emperor Wu of the Western Han Dynasty, so the reason for this must be related to Emperor Wu of Han. Confucianism has been baptized and developed through the pre-Qin and Qin dynasties, and by the Western Han Dynasty, it is not only the original philosophy, but also compatible with the ideas of the pre-Qin sons such as Taoism, Yin and Yang, and Fa.
During the period of Emperor Wu of the Han Dynasty, the great Confucian Dong Zhongshu proposed to "push the Kong clan and depose the Hundred Families", which is what we often mention later as "Confucianism, depose the Hundred Families". Because Confucianism is compatible with the ideas of other pre-Qin sons, the concept of kings and subjects is very much in line with the emperor's heart, and Confucianism advocates unconditional obedience that "the king wants the subject to die, the subject does not die and is disloyal", so Emperor Wudi of the Han Dynasty agreed to the reform proposed by Dong Zhongshu and began to promote Confucianism throughout the country. In this way, the status of Confucianism became high in an instant, and then both the princes and ministers and the ordinary people began to obey Confucianism, so there was the Book of Rites.
According to the historical records, the Book of Rites was compiled from the Western Han Dynasty and was completed after a long period of data collection and compilation by Dai Sheng and his disciples, so the idea of "planting pine trees and not planting cypress trees before the Tomb of The Son of Heaven" is likely to originate during the period of Emperor Wu of the Han Dynasty.
The mausoleum of Liu Che, the Emperor of the Han Dynasty, is also known as the MaoLing Tomb, and those who have visited the Mao Tomb will find that in addition to the tomb of the Emperor Wu of the Han Dynasty, there are also the tombs of the famous Western Han generals Huo Quyi and Wei Qing, these two generals had outstanding military achievements before their deaths, and they attacked the Xiongnu, because of the existence of these two people, the Xiongnu did not dare to invade the Han Dynasty, and it was also because of the two of them that Emperor Wudi of Han was able to complete the great cause of the ages and drive the Xiongnu to the north of the desert. Therefore, there are also two of their mausoleums in Maoling.
It is worth noting that in front of the mausoleum of Emperor Wu of han, there are only pine trees, but no cypress trees, and in front of the tomb of Huo Zhiwei Qing, there are cypress trees and no pine trees.
From this, it can be inferred that if it is not for posterity, the pine tree in front of the mausoleum of Emperor Wudi of Han is buried, then according to the creation time of the "Book of Rites", it can be roughly inferred that due to the unique Confucianism of the Han Dynasty, a large number of Confucians emerged for a time, in order to reflect their own value, Dai Sheng decided to compile the "Book of Rites", about the etiquette system of the varieties of trees planted in front of the mausoleum, referring to the tombs of Emperor Wu of Han and Wei Qinghuo, Dai Sheng wrote in the "Book of Rites" that "The Venerable Hill is high and there are many trees, and the lowly ones are sealed and there are few trees."
The tomb of the Son of Heaven is three blades high, and the tree is pine; the princes are half-wise, and the tree is cypress; the doctor is eight feet, and the tree is luan; the soldier is four feet, and the tree is locust; the people have no grave, and the tree is willow." Because later generations have always respected Confucian culture, the examination of the imperial examination system is mainly tested in Confucianism, so the record of this in the Book of Rites has been used by later generations, and there is also the saying that "cypress trees are not planted in front of the tomb of Tianzi".
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