Hatha Yoga Pradeepika Ch-2, Po-2

refer: http://yog-knowledge.blogspot.com/2010/12/hatha-yoga-pradeepika-ch-2-po-2.html

Method of performing Prâṇâyâma

The book says, Sitting in the Padmâsana posture the Yogî should fill in the air through the left nostril (closing the right one); and, keeping it confined according to one's ability, it should be expelled slowly through the sûrya (right nostril). Then, drawing in the air through the sûrya (right nostril) slowly, the belly should be filled, and after performing Kumbhaka as before, it should be expelled slowly through the chandra (left nostril).

Inhaling thus through the one, through which it was expelled, and having restrained it there, till possible, it should be exhaled through the other, slowly and not forcibly. If the air be inhaled through the left nostril, it should be expelled again through the other, and filling it through the right nostril, confining it there, it should be expelled through the left nostril. By practising in this way, through the right and the left nostrils alternately, the whole of the collection of the nâdîs of the yamîs (practisers) becomes clean, i.e., free from impurities, after 3 months and over.