To say "I rest my
case" means therefore that, as far as you are concerned, you've
done more than enough to prove your
point, and need say no more.
John: "You know your problem,
Bill? You're far too quick to descend to insulting
people who disagree with you."
:
Bill: "Don't be ridiculous! That's the sort of thing only a complete idiot would say."
: John: "I rest my case..."