Historical events or figures are another source of the origin. With five thousand years’ history, China has many historical events and figures which appeared in the language. Those celebrated events which leave deep impression on people and have great educational meanings are fixed in the form of four-character phrases. As we know well, such as “四面楚歌”,”负荆请罪”,”三顾茅庐”, all have a story in the history.
 Apart from the two sources mentioned above, religion is also a very important source. In China, the translation of Buddhist scripture is identified as the beginning of translation activities. Buddhism was introduced into China thousands of years ago and it gradually took root in the feudal society of China and flourished for a long time. So it is affected by the religion culture on the form of Chinese four-character phrases. Such as “大彻大悟” means completely understand, and “慈悲为怀” takes a meaning of one should be with a heart of mercy.
There are also a small part of Chinese four-character phrases are created by borrowing from foreign languages, like “以牙还牙” and “鳄鱼眼泪”. Chinese people use four-character phrases as an effective way for expressing the new phenomena in the current society.
2.2.3 Characteristics of Chinese Four-character Phrases
Chinese four-character phrases constitute a special part of the language and they are also in a large number. In addition, over 90% of these idioms are four-character idioms. Idioms display its differentiation from other general expressions or structures in its own distinctive features. The main features are: compactness, classical simplicity and elegance, varied figures of speech, reflecting Chinese traditional mentality.
A Chinese four-character phrase contains much meaning, so it is difficult to find the right words to equal the compactness in English. For example,”优胜劣汰” has a meaning which must be translated into an English sentence like” The efficient ones will win and the inefficient ones will be eliminated.” From the example, we could tell that compactness makes Chinese four-character phrases convenient to be used and easy to be memorized.
Also, a great number of Chinese four-character phrases are derived from classical works, which are the precious fruits of leading writers and linguists. These four-character phrases are of classical simplicity and elegance, which are influential on modern literature.
The third feature of our four-character phrases, varied figures of speech, means that the idioms carry richer meaning than its connotation. Different rhetoric devices, such as metaphor, parallelism, hyperbole, euphemism, and simile, are used to form the four-character phrases. They enrich the meaning and contents of the phrases. As we know,”锦上添花”,”气吞山河”,”青梅竹马” and so on.
The last but not least, language reflects the Chinese traditional mentality. Because language develops depending on thoughts for their contents, and different modes of thinking have different impact on language. Chinese traditional mentality makes the Chinese language full of connotation. Chinese people are born to be a sense of neatness and symmetry in structure and temperament of harmony and balance. I suppose, four-character phrases are partly the production of this pursuit. 跨文化交际下汉语四字成语英译研究(3):http://www.751com.cn/yingyu/lunwen_7901.html