The following are some reasons for engaging in Bi Gu:
- to acquire certain skills e.g. X-ray vision, remote diagnosis;
- Yin Shen practice (练阴神): if the Bi Gu period is extended, then it is easy for practitioners to perceive many visions. They need to master the Yang Shen (阳神) in order to differentiate the validity of these visions;
- to achieve certain breakthroughs and/or to overcome certain energetic blockages. At a certain level of mastery in the practice when the 14 meridians begin to circulate or while doing the Greater Orbit practice (大周天), one becomes aware of certain spots or areas when the energy is blocked. So a Bi Gu will enable the practitioner to obtain a clear view and the possible reasons and solutions for the blockage. Natural fasting in response to certain illnesses is not covered here.
A Bi Gu requires certain pre-conditions:
- the skill to obtain nourishment from the cosmos and external environments although the duration for this will not be too long;
- the skill to obtain nourishment from flowers, grasses, trees and forests;
- the skill to obtain nourishment from other practitioners, e.g. when one practitioner projects energy to another practitioner to see whether this would lead to some interesting extra-sensory abilities.
There are 3 main stages in a Bi Gu:
- cease intake of grains but possible to consume fruit and water (断谷)
- cease intake of all physical food but possible to have 1 glass of warm water (pre-boiled) each in the morning and night (断食); the practitioner needs to engage in daily walking practice (at least 5km, 1 hour long, paying special attention to co-ordinating the breathing and Yi Nian properly) and tree practice (20 minutes) at the same time (to mobilize internal Qi to move inside all the meridians, no need to do usual standing practice with back turned to the tree but sit directly on the grass or forests after walking); sitting meditation is done in the evening to regain balance and to determine which are the vulnerable parts/organs so that one can focus on the weak organs to strengthen them and then do the 5 internal organ practice, finishing off by returning the Qi back to Xia Tian (气归下田)
- Wo Gu (握固): maintain continuous sitting posture (double lotus position) inside an enclosure, no intake of food or fluids, no sleeping, natural external environment with flowers, plants and trees, need to mist water (containing medicine) around practitioner so that the body pores can absorb the moisture. There needs to be a guardian to protect the practitioner throughout this type of practice. The master also needs to call out the practitioner’s name repeatedly and regularly to provide an anchor into this reality. After 10 days or so in this state, the practitioner appears to enter into a different state of reality and will no longer be fully conscious. The practitioner sits until some vision appears and he has to then make sure that what appears is real and not illusionary. When this is achieved, the practice ends but no one can tell ahead of time whether the practitioner will “go off” or “return”. So the duration for this very challenging practice is totally open-ended. At the end of the practice, need to spray some water on the practitioner and offer honey drink followed by a good rest.
Towards the end of the Bi Gu, there is another practice that is done between 11pm to 1am at night. The beginning of this practice will coincide with the intake of solid food. But the process is gradual. First consume some fruit, nuts and a little water to break the fast before consuming solid foods. On the last night, food is consumed earlier and then the practitioner immediately gets into a sitting posture with the Ba Gua Hand Form (八卦子午式). The intention is that, hopefully, by 11pm the food is ‘gasified’ (气化) and when this happens, the practitioner must keep totally still and do their best to sit through the whole night so as to achieve a breakthrough to ‘see’ something.