南城以南思念不归北城以北旧人不回
[nán chéng yĭ nán sī niàn bù guī bĕi chéng yĭ bĕi jiù rén bù huí]
Translates as 'south of the southern city, longings do not return; north of the northern city, old acquaintances will not come back.' It expresses the feeling of lost connections where longing remains unfulfilled and old relationships cannot revert, representing separation.