This phrase is almost like a verbal talisman, designed to ward off bad luck after tempting fate: "Breaking that mirror didn't bring me any trouble, knock on wood."

这个短语几乎是一个口头护身符，用来在犯错误之后避开厄运：“打破了那面镜子不会带给我厄运，敲敲木头。”

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There is also a narcissistic delight in verbal dexterity, in dealing out the trenchant phrase.

FORBES: The New York Times' Mark Bittman Offers Poisoned Food For Thought