The Yoga Sūtra describes the flow of prāṇa with this lovely image: If a farmer wants to water his terraced fields, he does not have to carry the water in buckets to the various parts of his fields; he has only to open the retaining wall at the top. If he has laid out his terraces well and nothing blocks the flow of the water, it will be able to reach the last field and the furthest blade of grass without help from the farmer. In prāṇāyāma we work with the breath to remove blockages in the body. The prāṇa, following the breath, flows by itself into the cleared spaces. In this way we use the breath to make possible the flow of prāṇa.
The Heart of Yoga: Developing a Personal Practice
T. K. V. Desikachar
What is Prana? …
“’God is breath’ is the oldest Sanskrit writing… The Hebrew mystic states ‘God breathed into Man the Breath of Life and he became a living Breath.’
To be ‘in breath’ is to be ‘in God’. The Greek word for the taking in of the breath, ‘in-spiro’ means to be ‘in Spirit’. The taking of breath is a holy, divine function and those who aspire to Divinity must master Pranayama, the Yoga of Controlled Breathing.”
~ Swami Gitananda Giri Gurumaharaj