The phrase comes from Jane Austen's Emma, where Mr Knightley rebukes Emma at Box Hill after she publicly mocks Miss Bates, a turning point that forces Emma to recognise her own cruelty. Emma Approved, the modern web-series retelling of the novel, revisits that scene in episode 64, Boxx Hill, giving the scolding a short, quotable spoken form. Clips of the line have since circulated as a reaction sound for calling out thoughtless jokes and social slip-ups, because the literary context gives a simple put-down a sharper, more knowing edge.