There is a fight scene in one of my favorite movies in which the main character says
"Give them what for!"
I've hear this term many times before (usually from old south-eastern Americans,) but no one has been able to give me good explanation for the phrase. What does it mean and/or where does it come from? The best answer that I have heard so far goes something like this:
People used to say "What for did you do that?" so "what for" refers to their reason for doing something. Saying "give them what for" is another way of saying "Give them a reason…" (to run away, fight, or what ever.)
I'd really like to know how 'what' and 'for' came together and became a metaphor.