During the Tang Dynasty (618-907), there was a minister named Li Yifu. He was very good at flattering people, so his official position was raised higher and higher and he eventually became the prime minister. However, Li was a vicious man. When he talked with people he always wore a sweet smile, but he was conjuring up evil ideas in his mind.
One day, Li learned that a beautiful woman was put in prison. He sent for the prison officer and ordered him to set the woman free. The man followed the order and Li took the woman home.
Later, someone reported the case to the emperor. The prison officer was very afraid because he knew he had committed a crime by setting the criminal free. He went to Li for help, but Li ignored him and asked the man not to disturb him anymore. The man was so disappointed that he hanged himself.
Hearing the tragic suicide of the prison officer, another officer wanted to reveal the truth to the emperor. Li, however, knew of this plan and began to make false accusations against the officer. The foolish emperor believed Li's words and exiled the officer to a distant land.
The idiom "hide a dagger in a smile" has come to describe a person with a murderous intent behind his/her smile.
xiào lĭ cáng dāo
笑里藏刀
唐朝有个大臣叫李义甫，他很会奉承别人，所以他的官做得越来越大，一直做到了丞相。他是一个很恶毒的人。当他笑着对别人说话时，其实心里面想的是坏主意。
一次，有个年轻女子犯了罪被关进牢里。李义甫听说这个女子长得很漂亮，就叫监狱长把她放了。监狱长听从了他的话，把这个女子放了。李义甫就把这个美丽女子带回了家。
后来，有人向皇上告发了这件事。这个监狱长知道后，非常害怕，因为私放犯人是犯法的。他就向李义甫求助。谁知李义甫不但否认这件事，而且还叫这个监狱长别来烦他。这个可怜的人失望极了，就上吊自杀了。
有一个大臣听说了这件事，想向皇上说明真相，被李义甫知道了，他就先到皇上面前说这个官员的坏话。皇上听信了他的谗言，就把这个官员发配到很远的地方去了。
后来，人们就用它来形容一个人外表和气，内心阴险。
ān rán wú yàng
安然无恙
Escape unscathed; be safe and sound
