What's the 'harm' in letting her leave early? = I don't see any 'harm' in letting her leave early. = There's no 'harm' in letting her leave early. [=letting her leave early will not hurt anyone or cause a bad result]
I want to be sure that no 'harm' will come to her. = I want to be sure that she won't come to any 'harm'. [=that she won't be hurt in any way]
He claims that he didn't mean any 'harm'. [=that he didn't mean to hurt or bother anyone]
(..) What do you mean, sire? Neither your lands... nor the lands of your fellow conspirators... have ever suffered any real harm. For years, you have schemed against me! I'll not be made a scapegoat... for your failure to stop the Viking raids! (..)1958 The Vikings