The first half of a well-known proverb pair:
若要人不知,
除非己莫为 — 'If you want others not to know, then you yourself must not do it.' The saying is preserved in a poem attributed to the Han scholar Mei Sheng (
枚乘) 《
上书谏吴王》:
欲人勿闻,
莫若勿言;
欲人勿知,
莫若勿为 — a similar earlier formulation. The popular modern rhyme became proverbial through ballads and vernacular fiction.