Mastery of Prana is the first directive of Yoga.
The mastering of prana consists of awakening to it, getting it moving, letting it flow, then later learning to stop it from flowing at will. It is all seemingly contradictory. That is, prana was not flowing at the beginning, nor is it flowing at the end, but the difference between these two is that the first depicts a state of non-awareness and the second reveals the state of full Awareness.
Getting ahold of prana (like Atman and Brahman) is really taking account of them. People do not know about these facets of spiritual life, so they do not exist for them. Anything the mind can conceive of exists, but most is hidden from view.
Discovering the prana will soon take one into the mind proper — the chittakasha.
One must have the prana under control in order to control the mind. But people rush to sit in asanas, physical postures. Rather, they should begin with the yamas and niyamas. Make these your primary asanas: ahimsa-asana, asteya-asana, satya-asana, etc.
If prana is flowing you are alive; if not, you're dead. If your prana is controlled – now, that reveals Eternal Life and the illusion of death.
The ego subsists on ego. The connection between prana and ego is what Patanjali means when he indicates the klesha of clinging to life.
One must prepare for the leaking out of prana from the body in old age; but always keep control of the psychic prana that persists after the body drops.
Multidimensional: transmigrating in the lower three chakras: heaven, earth, and hell, under the auspices of the base prana.
Transdimensional: transcending the lower realms; and the cycle of rebirth, under the auspice of psychic prana.
If you have no control of prana, then you are never comfortable in groups of people, you have fear and doubt, you do not know where to put your limbs, and you have paranoia. Once prana is controlled, fear is made afraid of itself, doubt is made to doubt itself, your limbs settle into mudras for meditation, and sincere people get attracted to you. Got prana?
In this physical realm we move along the physical nadis (subtle nerves) of roads, rivers, canyons, wind currents, etc. When we become body and health oriented we begin to move among the gross nadis where blood flows, waste is ejected, and air moves in and out of our lungs. But how do we learn to move in the subtle realm? Through channels of thought. It is here that we begin to move more consciously through waking, dreaming, and deep sleep states, until we arrive in Brahman and move no more forever.
Food is nothing compared to the prana that makes it possible to enjoy the food. The prana circulating in the brain and tongue makes it possible to enjoy, and without it, it would be boring and tasteless. So if you are living a life of the senses only, the approach of death will rob you blind. Hurry, take the subtle energy inward. Ascend to higher levels.
It is not just that breathing helps the brain with oxygen; it is that prana helps the mind with free flowing thought. Mind and brain are different.
Kundalini abides mainly in the Svestini nadi, but She is present subtly in every center, already. Actually, She does not move. It is we, our awareness, that moves up the centers. Mother awakens it to do so.