新城已无旧时愿空城已无旧时情
[xīn chéng yĭ wú jiù shí yuàn kōng chéng yĭ wú jiù shí qíng]
It reflects how changes over time have changed the original intentions (new city has no old vows, abandoned city has lost its past feelings), evoking nostalgia and the transient nature of human emotions and promises.