STANdard parental-directive
"Stop That Awful Noise!" A "nuclear-level" version of da "first-and-foremost" or "usual" or "most frequently voiced" order --- "Be quiet" --- dat parents give their small children on innumerable occasions.
Lucy van Pelt super-loudly passed along da STANdard parental-directive from her mom --- a gentle request dat she and her visiting friends play their raucously-loud "cowboys and Indians" game more quietly --- to her toddler-brother Linus when he'd merely been shaking his baby-rattle; da joke, of course, was dat (A) da merely-faint sounds dat Linus was making were hardly even audible (especially compared to all of da shrill-'n'-noisy "shoot-'em-up bang" whooping and hollering dat Lucy and her friends had previously been carrying on with), and (B) she herself had absolutely b-e-l-l-o-w-e-d (indicated by a sawtooth-edged word-balloon instead of just a regular smooth words-enclosing line) said command ("Didn't you hear Mother?! STOP THAT AWFUL NOISE!!"), and so she herself was making an infinitely-louder racket than Linus had ever produced.