व्युत्थाननिरोधसंस्कारयोरभिभवप्रादुर्भावौ निरोधक्षणचित्तान्वयो निरोधपरिणामः॥९॥
III.9. vyutthāna nirodha saṁskārayoh abhibhava prādurbhāvau nirodhakṣaṇa cittānvayo nirodha pariṇāmah
Study of the silent moments between rising and restraining subliminal impressions is the transformation of consciousness towards restraint (nirodha pariṇāmah).
“Transformation by restraint of consciousness is achieved by study of the silent moments that occur between the rising of impressions and our impulse to restrain them, and between the restraining impulse and the resurgence of thought.
The key to understanding this wheel of mutations in consciousness is to be found in the breath. Between each inbreath and outbreath, we experience the cessation of breath for a split second. Without this gap, we cannot inhale or exhale. This interval between each breath has another advantage: it allows the heart and lungs to rest. I call this rest period ‘savasana’ of the heart and lungs.
Inhalation generates thought-waves, whereas exhalation helps to restrain them (I.34). The pauses between breaths, which take place after inhalation and exhalation are akin to the intervals between each rising and restraining thought. The mutation of breath and mutation of consciousness are therefore identical, as both are silent periods for the physiological and intellectual body.”
Light on the Yoga Sūtras of Patañjali, BKS Iyengar