Mahayana Vijñapti Sutra (Volume 72)

Youth Moon Reality (Candra Sūrya) again addressed the Buddha, saying: "World-Honored One, at the time of death, how does the consciousness abandon the body? How does the consciousness depart from the body? How does the consciousness know that it should now abandon this body?" The Buddha told Moon Reality: "Sentient beings receive retribution according to their karma. The stream of consciousness flows continuously, sustaining the body without cessation. When the allotted period is completed and the retribution ends, the consciousness abandons and discards the body, migrating to receive [a new existence] in accordance with [its] karma. Just as when milk and water are boiled together, through the fiery power of heat, the milk-fat, water, and cream each separate. Similarly, Moon Reality, when a sentient being's life ends, they disperse due to the power of karma. The physical form and consciousness, along with the sense bases and sense fields, each disperse. The consciousness serves as the basis, taking the dharmadhātu, along with dharmadhātu thoughts and wholesome/unwholesome karma, to migrate and receive another retribution."

Explanation: Youth Moon Reality said to the Buddha, "World-Honored One, when sentient beings are facing death, how does the ālaya-vijñāna abandon the material body? How does the ālaya-vijñāna leave the material body? How does the ālaya-vijñāna know that it should now abandon the material body?"

Based on what does the ālaya-vijñāna know it should now abandon the material body? It must be knowing the karmic seeds, deciding to leave the body based on those karmic seeds. The ālaya-vijñāna manifests and sustains the material body based on karmic seeds. When the karmic seeds indicate that at a certain moment it should no longer project the seeds of the four elements to maintain the existence of the material body, the ālaya-vijñāna knows at which minute the material body should cease to exist, that it should withdraw the four elements and cease projecting them. At that moment, the material body undergoes the dissolution of the four elements, the six sense objects cannot manifest normally, the six consciousnesses can no longer correctly perceive the six sense objects, the six consciousnesses gradually disappear, and the manas (mental faculty) and the tathāgatagarbha (Buddha-nature storehouse) depart from the body.

The Buddha told Moon Reality that sentient beings receive their karmic fruit according to their wholesome and unwholesome actions. The ālaya-vijñāna's continuous flow of seeds within the material body allows it to continue sustaining the material body's existence and functioning without interruption. Only when the lifespan is exhausted does the ālaya-vijñāna decide to abandon the material body, migrating to the next life's material body following the sentient being's wholesome and unwholesome karma.

For example, when milk and water are mixed together and heated by fire, the milk-fat rises to the top while the water remains below, and the milk and water separate from each other. Similarly, for sentient beings, due to karmic conditions, when their life ends, the five aggregates disperse and disintegrate; the physical body and the conscious mind separate, and the six sense faculties and six sense objects all separate.

The ālaya-vijñāna is the basis for the life of sentient beings. After it abandons the original material body, the seeds of the five aggregates return to the ālaya-vijñāna; the seeds of the four elements and the seeds of consciousness all return to the ālaya-vijñāna. When conditions are sufficient, the ālaya-vijñāna, following the mental power (thought) of the manas, along with the wholesome and unwholesome karmic seeds, migrates to the five aggregates of the next life. It then projects seeds again, forming the five-aggregate body of the next life, and the six sense faculties, six consciousnesses, and six sense objects all reappear.

Here, the "stream of consciousness" (shí liú) refers firstly to the seeds of the ālaya-vijñāna itself projecting moment by moment, enabling the ālaya-vijñāna to operate continuously without interruption. Secondly, it refers to the ālaya-vijñāna projecting the seeds of the seven consciousnesses, allowing the seven consciousnesses to operate continuously to ensure the life activities of the five-aggregate body. The ālaya-vijñāna continuously upholds our material body, ensuring its life activities continue without cessation. When this lifetime ends and the karmic retribution for this life is complete, the ālaya-vijñāna abandons this material body.