THE HATHA YOGA PRADIPIKA

original: "baddhapadmāsano yogī prāṇaṃ candreṇa pūrayet | dhārayitvā yathāśakti bhūyaḥ sūryeṇa recayet || 7 || prāṇaṃ sūryeṇa cākṛṣyapūrayedudaraṃ śanaiḥ | vidhivatkumbhakaṃ kṛtvā punascandreṇa recayet || 8 ||"
The Yogi, sitting in the Padmasana: the lotus posture, should draw in the Prana: the vital life force through the Chandra: the "moon" or left nostril. Having held it according to his capacity, he should then exhale through the Surya: the "sun" or right nostril. Then, drawing in the breath through the right nostril slowly, he should fill the abdomen; and after performing Kumbhaka: breath retention according to the rules, he should exhale again through the left nostril. 7 and 8.

Sitting in the Padmasana posture, the practitioner should fill the lungs with air through the left nostril (while closing the right one); and, keeping it held according to one's ability, it should be expelled slowly through the right nostril. Then, drawing in the air through the right nostril slowly, the belly should be filled, and after performing breath retention as before, it should be expelled slowly through the left nostril. 7 and 8.

original: "yena tyajettena pītvā dhārayedatirodhataḥ | recayecca tato'nyena śanaireva na vegataḥ || 9 ||"
Inhaling through the same nostril that was used for exhalation, and having restrained the breath to the limit of one's endurance, one should exhale through the other nostril slowly and not with force. 9.

Inhaling thus through the nostril through which the air was just expelled, and having restrained it there as long as possible, it should be exhaled through the opposite nostril, slowly and not forcibly. 9.

original: "prāṇaṃ cedidayā pibenniyamitaṃ bhūyo'nyayā recayet pītvā piṅgalayā samīraṇamatho baddhvātyajedvāmayā | sūryācandramasoranena vidhinābhyāsaṃ sadā tanvatāṃ śuddhā nāḍigaṇā bhavanti yamināṃ māsatrayādūrdhvataḥ || 10 ||"
If the air is inhaled through the Ida: the left energy channel, it should be expelled through the other. After inhaling through the Pingala: the right energy channel and holding the breath, it should be released through the left. By constantly practicing this method of alternate breathing through the "sun" and "moon" channels, the entire network of Nadis: subtle energy channels of the Yamis: self-controlled practitioners becomes purified after three months of practice. 10.

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 practicing in this way, through the right and the left nostrils alternately, the whole collection of the energy channels of the practitioners becomes clean—that is, free from impurities—after three months and beyond. 10.

original: "prātarmadhyandine sāyamardharātre ca kumbhakān | śanairaśītiparyantaṃ caturvāraṃ samabhyaset || 11 ||"
One should practice Kumbhaka (breath retention) four times a day: in the morning, at midday, in the evening, and at midnight, gradually increasing until the number of retentions reaches eighty per session. 11.

Breath retentions should be performed gradually four times during the day and night (morning, noon, evening, and midnight), until the number of retentions for a single session is 80, totaling 320 for the entire day and night. 11.

original: "kanīyasi bhavetsveda kampo bhavati madhyame | uttame sthānamāpnoti tato vāyuṃ nibandhayet || 12 ||"
In the lowest stage of practice, there is perspiration; in the middle stage, there is quivering of the body; and in the highest stage, one reaches a state of stillness. Therefore, one should control the breath. 12.

In the beginning stage of practice, there is perspiration; in the middle stage, there is a quivering or trembling; and in the final or third stage, one obtains steadiness or levitation; and then the breath should be made steady and motionless. 12.

The stages described in verse 12 refer to the physical markers of "purification" and the rising of internal energy (Prana). Perspiration is seen as the clearing of physical impurities, while quivering indicates the activation of the nervous system.