A dead letter is a dead letter
As a Chinese idiom, Pinyin is s ǐ Bi ā ob á ICH á n, which means to be entangled. It comes from the marriage story of awakening the world.
The origin of Idioms
The 38th chapter of the romance of awakening the world written by Xi Zhou Sheng in Qing Dynasty: "if it wasn't for Di Zhou's death, he would seize the opportunity to escape."
Idiom usage
Used as a predicate or attributive; used in writing.
A dead letter is a dead letter
exhaust oneself with persuasion - héng shuō shù shuō
recover one 's original simplicity ; return to one 's original nature - fǎn pǔ guī zhēn
mend the fold after the sheep have been stolen - wáng yáng bǔ láo
The magpie returns to the Phoenix - què fǎn luán huí
perpetrate whatever evils one pleases - zì yì wàng wéi