Pranayama: Nadi Shodhana

Excerpt from the Sri Vijnana Bhairava Tantra 

Commentary By Swami Satyasangananda Saraswati (Introduction):

“According to tantra, the subtle nature of prana is spandan, or pure vibration, at a very high frequency. Consciousness is not yet trapped in matter at this level, so cosmic prana, or spandan, is the vibratory field of pure consciousness. 

Just as consciousness has varying states of manifestation, prana too evolves through three different levels of energy in its descent from pure consciousness by which it can be known, intensified, channelled and merged back into its source, consciousness. 

These three levels of prana are also characterized by their quality of spandan or vibration on account of which the electro-magnetic field of prana surrounding the body is continuously expanding and contracting. 

It is this perpetual activity of expansion and contraction in the pranic field that is responsible for all dimensions of experience in life. When this activity diminishes or ceases, life itself is extinguished and all individual experience and perception retreats into the causal body, or vijnanamaya kosha.”