a broken relationship can never be repaired; a divorced couple are never reconciled
Proverb meaning that once a relationship (especially marriage) is broken, it cannot be mended, just as a broken mirror will never reflect light again. The literal image is 'a broken mirror will never shine again'.
As the proverb goes, 'a broken mirror will never shine again' — once a relationship is broken, it can never be repaired.
Similar proverb meaning 'spilt water will not return to the tray', emphasizing that what is done cannot be undone, often used for broken relationships as well.
Derived from the Classical Chinese maxim 破鏡不重照, “a broken mirror does not shine again,” in which the broken mirror represents a severed marital relationship.