“空穴来风”一词，江苏古籍出版社、上海教育出版社出版的《成语词典》都注为“原指户穴通风，后比喻流言乘隙而入”，同时引宋玉《风赋》中的“臣闻于师，枳句来巢，空穴来风”之语为证。还有一些《成语词典》作注与此相同。也许是以为“流言”即没有根据的话，就引申视“空? “Hole to the wind”, Jiangsu ancient books publishing house, Shanghai Education Publishing House “Dictionary of the idioms” are noted as “the original refers to the point of ventilation, metaphor rumors take the lead after entering”, while cited Song Yu “Fu” in the “ Chen Wen heard division, orange sentence to nest, hole to wind ”language as evidence. There are also some “idioms” for the same note. Perhaps it is thought that “gossip” is unfounded, then extended as "empty?