誓言是最蛊惑人心的毒药
[shì yán shì zuì gŭ huò rén xīn de dú yào]
Here, 'oath' or 'promise' is likened to being the most deceptive and harmful thing (like a poisonous drug) that tempts one deeply. This name indicates a wariness of promises because they tend to lead to pain when broken.