山无棱天地合才敢与君绝海可枯石可烂激情永不散
[shān wú léng tiān dì hé cái găn yŭ jūn jué hăi kĕ kū shí kĕ làn jī qíng yŏng bù sàn]
The phrase 'Only when mountains lose their crests and heaven meets earth dare I separate from you even if seas dry up and stones decay our passion will never fade' expresses eternal love with poetic exaggeration. Mountains and stones are seen as everlasting, making separation impossible unless nature itself changes.