The quite I wrote was mentioned by Machiavellian in his book, but is not his. As far as I'm aware it's just old folk expression. It was often told to me by an older army friend who trained me advised me on life when I was young and he would tell me also after saying it "because your enemy wants to see you dead and staying alive is your top priority". Didn't read any of Machiavellian's books, but I know enough about him to know that I wouldn't like them. I can only see it as a benefit of knowing what schemes my enemies might use against me. Do you have any insight on him?