save a man hanging himself by pulling his feet—one’s action is just the opposite to what one wishes; one’s action runs counter to one’s desire ❍ 儿子犯罪之后你想帮他逃跑那犹如～。你应该让他投案自首才是。You want to help your son to escape after he has committed the crime. But what you are doing runs counter to your desire just like trying to save a man hanging himself by pulling his feet. You should tell him to surrender himself to thepolice.