Hatha Yoga Pradipika- Ch-2.2 Understanding Prana (energy) for Mindfulness
Hatha means balancing the polarity present outside at physical, mental, energy level.
the commentator of Patanjali says Yoga is Samadhi ( deepest meditation or mindfulness).
Hatha Yoga , therefore , means practices to bring balance and harmony in outer life to awaken to mindfulness or deep meditative state.
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