I rest my case
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..."
: Bill: "Don't be ridiculous! That's the sort of thing only a complete idiot would say."
: John: "I rest my case..."