Tā fāshì jiùsuàn dào le Huángquán yě búhuì wàngjì tā.
He swore he wouldn't forget her even in the underworld.
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history
In ancient Chinese cosmology, 黄泉 was the underground realm where souls went after death - named for the yellow-colored springs believed to exist deep underground. It appears in texts as early as the 《左传》 (5th century BC).
culture
The famous line 不到黄泉不相见 comes from the 《左传》, where Duke Zhuang of Zheng swore never to see his mother again. It's now used as a dramatic expression meaning 'until death.'
