After the ālayavijñāna departs, why doesn't the corpse immediately disappear and decay?

When a person dies, the manas and the ālayavijñāna leave the physical body, and the body becomes a corpse. It changes from being sustained by that sentient being's own single ālayavijñāna to being jointly sustained by the ālayavijñānas of many sentient beings, at which point it becomes an insentient object. Insentient objects are all composed of the four great elements. When they decay, the four great elements must gradually, in an orderly and continuous manner, return from the insentient object to the ālayavijñānas of the various sentient beings. How long this process takes is uncertain; it is determined by the karmic power of the sentient beings, and also depends on how solid and durable the insentient object is. The decay of a corpse begins as soon as the ālayavijñāna leaves the physical body; it is just that at first it is not easy to detect. The speed of decay also depends on the surrounding temperature and environment, as well as the amount of moisture in the corpse. This is because temperature and humidity are conditions for bacterial reproduction—the more and faster the bacteria multiply, the faster the corpse decays. In the end, only bones remain, which become part of the material world (the inanimate environment) of the universe, mountains, rivers, and the great earth. After a certain time, the bones too will weather, decompose, and cease to exist.

In the short period right after the physical body dies, it is still sustained by a single ālayavijñāna, and the conscious mind may possibly be reborn again—for example, the worldly notion of "returning from death to life" is based on this principle. So, when a person has just died, while the ālayavijñāna and the manas have not yet completely departed, organ transplantation must be performed within a short time. The so-called short time means within a few hours—within those few hours, the ālayavijñāna is still sustaining the body's organs, the nerves are still functional, the cells are still functional, and the muscle tissue is still functional. When an organ is transplanted into another person's body at this time, if the two people's manas are incompatible, a state of rejection will occur; if the two people's manas are compatible, and their relationship and feelings toward each other are good, no rejection phenomenon will appear, and the handover between the two ālayavijñānas can be completed. If the manas is attached to the body's organ and refuses to give it to another, the handover between the two ālayavijñānas will not go smoothly, and other uncomfortable symptoms may appear—that is, the body's rejection response.

Take another example: if a person's finger is severed, within a short time the finger still has warmth, the blood vessels are still functional. Within this time frame, blood can still flow through, the blood vessels are still usable, the nerves are still usable, and it can be reattached. When it is reattached, it can reconnect with the hand, and before long it will heal and be able to move again. But once too much time has passed, the finger becomes jointly sustained by the ālayavijñānas of the sentient beings of collective karma, and reattaching it to the hand is then useless—no matter how it is sutured, it will not work, just like attaching a piece of wood.