I don't know if I'm showing my age or Irish ethnicity, but my childhood was littered with sayings like that which didn't entirely make sense at the time but you still got that they carried a threat or warning.
Now that I'm older and often asked to work with companies on their communication strategies, I am amazed at how relevant & salient that warning is, whether communicating with an external audience of clients or internal teams.
Of course, no one wants to damage their reputation or relationships, it just kind of happens doesn't it? This post from Dr Travis Bradberry on the 11 things people heard you say, even when you were actually trying to say the complete opposite offers a tremendous insight that could save you a lot of grief. A classic one but not on the list is the phrase 'I'm willing to...' which tests show invariably prompts people to believe that the person saying it feels quite the opposite; grudgingly prepared to do something but deeply resentful of the request. More than just use of words, it's a kind of verbal body language to protect the impact of your words. Definitely worth a look, if only to see how many you use in everyday language.