English Original
During the Northern and Southern Dynasties, as the State of Chen (A.D. 557-589) faced its demise, Xu Deyan, the princess's husband, broke a bronze mirror in two. Each kept one half as a token in case they were separated. They soon lost contact, but the two halves of the mirror later enabled them to reunite.
This idiom refers to the reunion of a couple after separation or breakup.
中文翻译
南北朝时期，陈国（公元557-589年）濒临灭亡之际，公主的丈夫徐德言将一面铜镜摔成两半。两人各持一半，作为日后万一失散的信物。不久后，他们果然失散，但正是凭借这两半镜子，他们最终得以重逢。
这个成语用来比喻夫妻失散或决裂后重新团聚。