During the course of practice, one day you will feel that you have separated yourself from the body. You will have immense joy mixed with fear, joy in the possession of a new, light, astral body, fear owing to the entry in a foreign, unknown plane. At the very outset, the new consciousness is very rudimentary in the new plane, just as in the case of a pup with newly opened eyes in the eighth or tenth day on the physical plane. You will only feel that you have a light airy body and will perceive a rotating, vibratory limited astral atmosphere with illumination of golden lights, objects, beings, etc. You may feel you are rotating or floating in the air and consequently there is the fear of falling.
You will never fall; but the new experience of subtlety generates novel feelings and sensations in the beginning. How you leave the body, remains unknown at the outset. You are suddenly startled, when you have completely separated, and when you enter into the new plane, sometimes with blue-coloured sphere around, sometimes with partial illumination (Prakasha) mixed with darkness while at other times with extremely brilliant golden, yellow diffused illumination. The new joy is inexpressible and indescribable in words. You will have to actually feel and experience yourself (Anubhava). You will have to eat yourself. You are unaware of how you have left the body, but you are fully conscious of your returning. You gently feel as if you glide on a very smooth surface; as if you enter smoothly, gently through a small whole of fine tube with an airy, light body. You have an airy, ethereal feeling. Just as air enters through the crevices of a window, you enter with the new astral body into the physical body. I think I have expressed the idea lucidly. When you have returned, you can markedly differentiate the life in the gross and subtle planes. There is an intense craving to regain the new consciousness and to remain in that state always. You are not able to stay for a period longer than 3, 5 or 10 minutes in the new region. Further, you can hardly leave the body at will, through simple willing, in the beginning. By chance, through efforts, you are able to separate from the body in a month in the course of Sadhana. If you plod on with patience, perseverance and firmness, you will be able to leave the body at will and stay for a longer time in the new plane with the new subtle body. You are quite safe from the identification with the body. You have made conquest of Deha-Adhyasa, only if you can leave the body at will and only if you are able to stay in the new region for 2 or 3 hours. Your position is quite secure then and not otherwise. Mouna or the vow of silence, solitude, living alone are sine qua non to achieve this end. If circumstances prevent you to observe Mouna, strictly avoid long talk, big talk, tall talk, all unnecessary talks, all sorts of vain discussions, etc., and withdraw yourself from society as much as possible. Too much talk is simply wastage of energy. If this energy is conserved by Mouna, it will be transmuted into Ojas or spiritual energy which will help you in the Sadhana. Speech is Tejomaya Vak according to Chhandogya Upanishad. The gross portion of fire goes to constitute bone, the middle portion to form marrow; and the subtle portion of fire to form speech. So speech is a very powerful energy. Remember this, remember this, remember this always. Observe Mouna for 3 months, 6 months or 1 year. If you cannot do for months continuously, observe for a day in a week, just as Sri Mahatma Gandhiji did. You must draw inspiration from Mahatmas like Sri Krishna Ashramji Maharaj who is now living absolutely nude for the last many years in the icy regions of Himalayas, near the origin of the Ganga, Gangotri. He is observing Kashta Mouna, a rigid vow of silence for many years. (In Kashta Mouna you do not communicate your thoughts to others even in writing or by signs). Why not you also become a Krishna Ashram of wide repute and glory? After continuous, hard practice, you will be able to separate yourself from the body, very frequently. There is established a habit. As soon as you silence the thought, and calm the mind, the mental habit of slipping from the physical body supervenes automatically. There is no difficulty then. The mind enters the new groove and appears on a new stage or platform.
You can simply, by mere willing, travel to any place you like with the astral body (astral travel, astral journey) and there materialise by drawing the necessary materials either from Asmita (Ahamkara) or the universal storehouse-ocean of Tanmatras. The process is very simple to occultists, and Yogins who know the rationale, the detailed technique of the various operations, albeit it seems extraordinary to poor mundane creatures with diverse emotions, passions and attachment. Thought-reading, thought-transference also can be quite easily performed by those who can function with the astral body. Concentrated mental rays can penetrate opaque walls, just as X-rays pass through bones.
You first separate yourself from the body, then you identify yourself with the mind and then you function on the mental plane, with this fine body, just as you do on this earth plane. Through concentration, you rise above body-consciousness; through meditation, you rise above mind; and finally through Samadhi, you become one with Brahman. These are the three important, Antaranga Sadhanas (internal means), in the achievement of final beatitude.