Origin and Negative Roots: This idiom originates from the ancient Chinese classic, the Book of Odes (《诗经》). In the poem “Qiao Yan” (《巧言》), the line “巧言如簧,颜之厚矣” critiques a slanderer, meaning “His clever words are like a reed pipe, how thick his face is!” From its inception, the term was associated with insincere, harmful, and shameless speech.
Sincerity over Polish: Chinese culture, influenced by Confucian values, often prizes sincerity (诚恳, chéngkěn) and straightforwardness over flowery, elaborate speech. While eloquence (口才, kǒucái) is appreciated, it becomes suspect when it feels too polished or self-serving. 巧舌如簧 perfectly captures this suspicion. It implies that the speaker is hiding their true intentions behind a beautiful facade of words.
Comparison to “Silver-Tongued”: In English, calling someone “silver-tongued” can be a compliment, suggesting charisma and charm. It leans negative only depending on context. 巧舌如簧, however, is almost exclusively negative. It carries a much stronger accusation of manipulation and deceit. If a Westerner is a “smooth operator,” a person described as 巧舌如簧 is a “dangerously smooth operator.”