白天触碰不到黑夜黑夜触碰不到白天
[bái tiān chù pèng bù dào hēi yè hēi yè chù pèng bù dào bái tiān]
"Day Cannot Touch Night, Night Cannot Touch Day" poetically conveys the unreachability between two distinct yet co-existing worlds, symbolizing unrequited love or eternal separateness.