Book Three of the Yoga Sutras of Patanjali…..
I can’t emphasize this enough…if you are interested in knowing the root of the practice…far beyond the physical movement you make on the mat…the Yoga Sutras of Patanjali is where to begin, because this is where you begin.
Book Three of the Yoga Sutras explains the 6th, 7th and 8th limbs of Yoga – Dharana (concentration), Dhyana (meditation) and Samadhi (contemplation/enlightenment/self-realization). Practicing all three is called Samyama. And this may be the most challenging part of Yoga.
It takes physical and mental strength to breathe and move, physical and mental strength to be sure you’re behaving “right.” Physical and mental strength to let go of outside distractions. But, in my opinion and experience in practice, it takes much MUCH more than physical or mental “strength” to concentrate, meditate and experience something greater than you ever thought you were.
This is a part of the practice I cannot explain, mainly because I’m still working, every day, to experience it myself.