Through the practice of Bi Gu, we provide the conditions for our body to become ‘empty’. On the third day of the Bi Gu, it is common for the legs to start trembling and shaking. With the added effort to be silent during all this while, we aim to motivate the body Qi to return to the Xia Tian (气归下田) and for the Xia Tian (下田) to begin to gently move. When the Xia Tian (下田) is activated and begins to vibrate, there are 2 possibilities for the energy: to move upwards or to move downwards relative to the Xia Tian (下田). The practitioner has to watch inwardly like a detached observer to see where and how the energy pathways unfold from the Xia Tian (下田). If the energy decides to go upwards, then the practitioner has to decide whether the downward energy arising from the effects of the food that is just consumed is greater than this upward moving energy. This will determine the ultimate direction of this energy, i.e., whether it moves upwards or downwards or whether it spirals and spins. Practitioners who are older in age are advised to spin the energy before allowing it to rise up. Practitioners who are younger in age can just simply observe the whole movement without any interference, and to patiently wait to see if the energy begins to spin.
After the Bi Gu, sitting meditation is done at night between 11pm to 1am. Using the Real breath to lead the Yin in Yang Qi to rise and the Yang in Yin Qi to descend (用真人之气带阴中之阳气上升，阳中之阴气下降) so as to meet at the Zhong Gong (中宫) in order to generate some sort of movement there. After consuming food at the end of the Bi Gu, we patiently await the 2 Gong – the Zhong Tian (中田) and Xia Tian (下田) – to appear but we can do the 5 internal organ practice to see whether the organs begin to be activated or not. Then return the Qi back to the Xia Tian.
The nightly sitting sessions must be done on the bed. The focus will be on the breathing (进风) for alchemy (“letting in the wind”), stabilizing the body (封炉) (“sealing the furnace and cauldron”), and Xin Fa (心法) – “movement of the internal medicine” (内药在动). At 11pm, wake up to sit, stabilize the mind and body, listen to the sounds of the human universe (internal) and the cosmos (external). During sitting, the external Qi will rise instead of sinking down and the whole person will become ‘empty’ and without “roots”. So the Qi will rise, giving a sense of floating. There will be lights appearing in front of your eyes but do not open your eyes. Slowly watch the moving lights.
The Bi Gu is a practice to understand and know ourselves. It can last 3, 5 or 7 days. The whole process is beneficial whichever number of days you choose or if you are in a state of dis-ease. After 3 days, one can discover their own health issues. And after 5 days, one can identify one’s weakest link in the body. There is still some fecal matter after 3 days of fasting but after 5 days, the large intestines will be relatively empty. During fasting, all the other practices are to be done daily. If we extend this process to 21 days, then we will be able to “see” many things. The Bi Gu process can come to an end only after the practitioner is able to “see” visions and various scenes. So the first advantage of Bi Gu is to discover one’s weakest spot(s) and, secondly, the weaker cells or diseased cells will be destroyed in the process. In this fashion, the overall quality of one’s health will be improved. It takes 7 X 7 = 49 days for the body’s blood to be renewed. 9 X 9 days = 81 days is even better.
On Day One of the Bi Gu, the aim is to become aware of and sense the movement of the 5 organs, know the sounds of these movements, and to have a clear idea what happens when one organ is linked to another organ (taste). The 5 internal organs practice is also known as the Small Pill Return practice (小还丹), so generating an internal medicine is the end result, not just knowing the “taste” of each organ. So is it possible to achieve the perfect harmony of the 5 elements and the integration of all the organs? The ideal situation is similar to the case of the Five Generals responding in sync when summoned by the Emperor. In practice, when we sit and stabilize ourselves, can all the 5 organs become activated and rise at the same time? And if we decide to descend, can the organs also respond accordingly? The second aim is to find out what happens to our internal organs if we do not receive nourishment from the usual sources from the external environment. When we fast, our Existential Energy will be used up slightly in the beginning so we need to rely on tapping into the Cosmic Energies to sustain ourselves. However, when the Cosmic Energy is absorbed into the body, how can these energies reach the respective internal organs? The third aim is to really get to know our internal organs: which organs are “hard” and which ones are “soft”? If we look at water, can our internal organs become like water? Would our internal organs obey our every command, e.g. becoming rounded when we want the organs to be rounded, becoming flat when we want the organs to be flat, starting and stopping the movement at our command? We aim to accomplish these on Day One of the Bi Gu.
During the first day of the Bi Gu retreat, there are 5 self directed requirements for each practitioner: listening within the heart (not the physical heart) (心内听) to bring back the Shen (收神), to bring back the body (收身), to bring back the vision (收视), to bring back the (inner) heart (收心), to bring back the Yi (收意), so as to treat oneself well and to treat one’s life well. The first and last requirements are the most important. The other three requirements are easier within our control. If you are not able to bring back the Shen on the first day, then take your time and do the practice slowly in the right direction. The same applies to stilling the body after you bring back the body.