四字熟語　よじじゅくご

四字熟語　よじじゅくご　Four character idiomatic compounds
Some of them are quoted from old Chinese books. However many of them are just simplified expression. Japanese does not like complicated long sentence. For an example,
朝蝿暮蚊 ちょうようぼぶん つまらない人間が集まってきて困ることのたとえ。
Worthless people thrives and rampant at will like as if morning flies and evening mosquitoes. by 山本賢