许下地老天荒的诺言共谐海枯石烂的恋歌
[xŭ xià dì lăo tiān huāng de nuò yán gòng xié hăi kū shí làn de liàn gē]
Direct translation would be: 'Make an eternal vow till the earth is barren, sing a love song together until the sea runs dry.' Reflects a longing or commitment for an undying love.