Making a Longevity Coffin (heshoumu)
Having one's coffin made in advance during one's lifetime. 'Longevity coffin' is a euphemism for a coffin.
This refers to having one's coffin prepared while still alive. In traditional society, this was an act of arranging for one's posthumous affairs, usually undertaken in old age or poor health. 'Longevity coffin' is a euphemism for a coffin, carrying an implication of wishing for a long life. Old almanacs specified particular auspicious days for 'making a longevity coffin,' believing it should be done on a fortunate date to accumulate hidden merit for oneself or to avoid clashing with inauspicious directions or deities during the crafting process. In modern society, pre-writing a will or purchasing a pre-need contract are common corresponding concepts, but the traditional ceremony of 'making a longevity coffin' has become extremely rare.