The moment a human egg and sperm unite, the consciousness of a bardo body enters the zygote. Although it is already a life at this point, there is no physical body. As the embryo continues to grow and becomes more mature, a full body will be formed at last. During the course of growing up, an attachment to this being will be developed, which immediately becomes the alaya consciousness, the base of consciousness. The fact that we still have breath, heartbeat, blood circulation and so forth when in deep sleep while other senses stop functioning indicates the existence of certain energy. This energy is the alaya consciousness.

The alaya consciousness, like the water deep down in the ocean, remains still at all times, no matter how violent the ocean swells. The water closer to the surface, however, will move depending on the force of the gale and its depth. The waves, the water that moves, refer to the five sense consciousnesses and the sixth consciousness.

~ Depicted from "THE HANDBOOK FOR LIFE"S JOURNEY : On Death And Rebirth-Understanding Death