From
刘禹锡's Tang-dynasty essay
《陋室铭》 (Inscription for My Humble Room). Full couplet:
谈笑有鸿儒,
往来无白丁 - 'I chat and laugh with great scholars; no plain commoners pass through.' The essay defends the dignity of a small, simple house, arguing that a room is ennobled by the company it keeps, not by its size or decoration.