Second half of a Han-era proverbial couplet preserved in 《
汉书·
枚乘传》 and widely repeated in later literature:
若要人不知，
除非己莫为 — 'If you wish no one to know of it, then you yourself must not do it.' The logic is airtight: secrets leak, so the only fool-proof way to hide a misdeed is never to commit it. Enduring favourite of moralists, school teachers, and anti-corruption officials.
