The fairly advanced and the least advanced yogi should practice as much as possible the gathering of prana in the Central Channel, whatever method he uses, before the sign of death appears. He should also try to raise the Four Emptinesses and the (Three) Bodies of Buddha. In addition, he should try to hold the Light of Sleep and the Illusory Body of Dream. It is important to practice these teachings before death comes.
The Instruction on Recognizing the Signs of Death
One should know the explanations on the subsidence of the Crude Twenty Lights; that can be found in other books. In brief, the signs of death are as follows: When the earth-element subsides into the water-element, the outer phenomenon is that one cannot move or hold his body--as if the body is collapsing and sinking so that the dying person feels like exclaiming "Hold me up!" The inner phenomenon is the experience of seeing a mirage. When the water-element subsides into the fire-element, the outer phenomenon is that one feels thirst, a burning in the mouth and nose, and that the tongue shrivels; the inner phenomenon is seeing smoke. When the fire-element subsides into the air-element, the outer phenomenon is the experience of decrease in the warmness of the body; the bodily warmth will gather at the end of the body. The inner phenomenon is seeing a tiny light like that of a glow-worm.
When the subsidence of the delusory mind-prana takes place, the outer phenomenon is the long exhaling of the breath. The dying person feels his breath to be hard and rough, and finds it impossible to stop the exhalation even if he wills to do so. The inner phenomenon is the seeing of a steady (unwavering) lamplight. Thereupon, the so-called "First" Voidness or first perception appears, which is like seeing the moonlight shining in a cloudless sky. After the emergence of the "First" Voidness, comes the so-called "Second" Voidness or the Extreme Voidness. The dying one sees an augmenting Voidness, bright and glaring like the sunlight blazing from a clear sky; this is called the Stage of Augmentation. After the subsidence of this stage, comes the stage called the "Attainment," in
which the dying one feels his consciousness becoming dim and sluggish; this experience is like seeing a dark sky. Then comes the complete cessation of all thoughts, and the dying one experiences complete darkness.
Thereafter, his consciousness awakes from darkness, and the "Universal Voidness" appears; this experience is like seeing a clear and unobscured sky under the radiant sunlight at dawn. This light is the real Fundamental Light.