Don’t write anything you can phone. Don’t phone anything you can talk. Don’t talk anything you can whisper. Don’t whisper anything you can smile. Don’t smile anything you can nod. Don’t nod anything you can wink.

Earl Kemp Long
Earl Kemp Long (1895-1960) American politician, orator.
(Attributed)

Advice on political discretion. Widely attributed, but with no primary sourcing or particular context I can find. Quoted in his biography, Michael L. Kurtz, Earl K. Long: The Saga of Uncle Earl and Louisiana Politics, ch. 7 (1990).