II.49 tasmin sati śvāsa-praśvāsayor gati-vicchedaḥprāṇāyāmaḥ
When that [āsana] is accomplished, prāṇāyāma, breath control, [follows]. This consists of the regulation of the incoming and outgoing breath.
“Prāṇāyāma as breath control is an ancient practice that can be found in the old Brahmana texts. Vyāsa explains that the svasa from this sūtra is the intake of air from the outside, and pravasa, the exhalation of air from the stomach. He defines prāṇāyāma to be the suspension, or absence, of both—in other words, the suspension of breath.”
The Yoga Sūtras of Patañjali, Prof. Edwin F. Bryant
“Prāṇāyāma, the fourth constituent of yoga, is what the heart is to the human body.
It is interesting to note that Patañjali expressly advises the sadhaka to do prāṇāyāma only after attaining perfection in āsana. For the first time, he shows a distinct step in the ascent of the ladder of yoga, whereas he has not stipulated progression for the other aspects.
Normally the flow of breath is unrestrained and irregular. Observing these variations, and conditioning the mind to control the inflow, outflow and retention of the breath in a regular, rhythmic pattern, is prāṇāyāma.”
“Prāṇā is an auto-energizing force which creates a magnetic field in the form of the Universe and plays with it, both to maintain, and to destroy for further creation. It permeates each individual as well as the Universe at all levels. It acts as physical energy; as mental energy, where the mind gathers information; and as intellectual energy with a discriminative faculty, where information is examined and filtered. This same prāṇā acts as sexual energy, spiritual energy, and cosmic energy. All that vibrates in the Universe is prāṇā: heat, light, gravity, magnetism, vigour, power, vitality, electricity, life and spirit are all forms of prāṇā. It is the cosmic personality, potent in all beings and non-beings. It is the prime mover of all activity. It is the wealth of life.”
“This self-energizing force is the principle of life and of consciousness. It is the creation of all beings in the Universe. All beings are born through it and live by it. When they die, their individual breath dissolves into the cosmic breath. Prāṇā is not only the hub of the wheel of life, but also of yoga. Everything is established in it. It permeates life, creating the sun, the moon, the clouds, the wind, the rain, the earth and all forms of matter. It is both being (sat) and non-being (asat). Each and every thing, or being, including man, takes shelter under it. Prāṇā is the fundamental energy and the source of all knowledge.”
“Prāṇā (energy) and citta (consciousness) are in constant contact with each other. They are like twins. Prāṇā becomes focussed where citta is, and citta where prāṇā is. In yogic texts, it is said that as long as the breath is still, prāṇā is still, and hence citta is still. All types of vibrations and fluctuations come to a standstill when prāṇā and citta are steady and silent.
The wise yogis studied this connection between breath and consciousness and advocated the practice of prāṇāyāma to stabilize energy and consciousness.”
Light on the Yoga Sūtras of Patañjali, B.K.S. Iyengar
“It is difficult to explain Prāṇa, as it is to explain God. Prāṇa is the energy permeating the universe at all levels. It is physical, mental, intellectual, sexual, spiritual, and cosmic energy. All vibrating energies are prāṇa. All physical energies such as heat, light, gravity, magnetism, and electricity are also prāṇa. It is hidden or potential energy in all beings, released to the fullest extent in times of danger. It is the prime mover of all activity. It is energy which creates, protects, and destroys. Vigour, power, vitality, life and spirit are all forms of prāṇa.”
“Prāṇa means breath, respiration, life, vitality, energy or strength. When used in the plural, it denotes certain vital breaths or currents of energy (prāṇa-vayus). ‘ayama’ means stretch, extension, expansion, length, breadth, regulation, prolongation, restraint or control. ‘Prāṇāyāma’ thus means the prolongation of breath and its restraint.”
“Prāṇāyāma is an art and has techniques to make the respiratory organ to move and expand intentionally, rhythmically and intensively. It consists of long, sustained subtle flow of inhalation (pūraka), exhalation (rechaka) and retention of breath (kumbakha). Pūraka stimulates the system; rechaka throws out vitiated air and toxins; kumbakha distributes the energy throughout the body. The movements include horizontal expansion (dairghya), vertical accession (āroha) and circumferential extension (viśālatā) of the lungs and the rib cage.”
“The disciplined breathing helps the mind to concentrate and enables the sādhaka to attain robust health and longevity.”
“All stages of [Ujjāyī Prāṇāyāma (Expanding Conquest Breath control)] except those with retentions may be done at any time. However, if the heart feels heavy, full or painful, or the diaphragm is hard, and if you are agitated or the heart-beat is abnormal, lie down…”
Light on Prāṇāyāma, B.K.S. Iyengar
II.50 bāhyābhyantara-stamba-vṛttiḥ deśa-kāla-saṅkhyābhiḥ pariddṛṣṭo dīrgha-sūkṣmaḥ
[Prāṇāyāma] manifests as external, internal, and restrained movements [of breath]. These are drawn out and subtle in accordance to place, time, and number.
“Moving on to the second part of the sūtra, all these different types of breath restraint are regulated by place, deśa, that is, the surface area that is reached by the breath, says Vyāsa. He understands time as the seconds of duration of these cessations of the flow of breath, and number as how many sequences of inhalations and exhalations are restrained, and whether they are mild, middling, or intense in nature.”
“Time, kāla, refers to differing durations of each individual exhalation, inhalation, and retention,… Number, saṅkhyā, is the number of repetitions, or rounds of each cycle of inhalations, exhalations, and retentions at one sitting.”
“In other words, say the commentators, one can increase the duration of these intervals of breath restraint so that they become more and more prolonged and imperceptible in terms of the movement of air.”
The Yoga Sūtras of Patañjali, Prof. Edwin F. Bryant
“The first three components of prāṇāyāma are regulated inhalation, exhalation and retention; all are to be performed, prolonged and refined according to the capacity of the aspirant. The components are to be observed with regard to place (deśa), here meaning the torso, kāla indicating length of breath and saṁkhyā, indicating precision.”
“There are two types of retention in prāṇāyāma. They are the interruption of the breath flow following either the in- or outbreath. The movements of the breath and the pauses between them are regulated and prolonged according to the capacity of the lungs (deśa), the duration and measured regulation of the breath (kāla) and the degree of refinement and subtlety (saṁkhyā) of the sādhaka. Mastery is attained by practising in harmony, with rhythmic regulation (paridṛṣṭa).
Focus on the regulation of breath (prāṇā vṛtti), exhalation (bāhya vṛtti), inhalation (antara vṛtti) and retention (stambha vṛtti) is called sabīja (seed) prāṇāyāma as attention is on the breath itself.
Inhalation moves from the core of being – the seer – towards the consciousness. As mahat or cosmic intelligence is the first principle for nature’s activity, its individual counterpart, citta, acts to stir the soul to activity. The inbreath is made to touch the five sheaths of the body: ānandamaya, vijñānamaya, manomaya, prāṇāmaya, and annamaya, or the elements: ākāśa, vāyu, tej, āp, and pṛthvi; while the outbreath touches in the reverse order.
Bracing of the inbreath is the evolution of the soul or the ascending order of the puruṣa. When the self comes in contact with the physical body, inhalation is complete. Here, the puruṣa embraces prakṛti. The outbreath moves from the external body towards the seer, layer after layer. It is involution, or the descending order of prakṛti to meet its Lord, puruṣa. If the inbreath is the divine union of puruṣa with prakṛti, the outbreath is the union of prakṛti with puruṣa. Retention of the former is antara kumbhaka, retention of the latter is bāhya kumbhaka. If antara kumbhaka establishes consecration of the seer (svarūpa pratiṣṭha), bāhya kumbhaka frees one from the four aims of life (puruṣārtha śūnya).”
Light on the Yoga Sūtas of Patañjali, B.K.S. Iyengar
II.51 bāhyābhyantara-viṣayākṣepī caturthaḥ
The fourth [type of prāṇāyāma] surpasses the limits of the external and the internal.
“The fourth, caturthaḥ, type of prāṇāyāma, says Vyāsa, refers to the total suppression of breath and so, like the kumbhaka mentioned previously, also involves the cessation of inhalation and exhalation. Vijñānabhikṣu calls it kevala-kumbhaka, pure kumbhaka. In his Yogasāra commentary, he quotes the Bṛihan-nāradīya Purāna as referring to it as śūnyaka. The commentators are not overly helpful in clarifying the precise difference between the third type of prāṇāyāma, kumbhaka, and the fourth type, caturthaḥ. As is the case with so much in the sūtras, it is clear that these are techniques to be experienced by practice rather than understood intellectually. Vyāsa states that the third type of suppression is brought about by a single effort, whereas the fourth takes place gradually with prolonged effort. Apparently, kumbhaka is performed independently of the suppression of breath in rechaka and pūraka that utilizes the system measurements: it is thus limited in duration. Caturthaḥ, in contrast, says Vijñānabhiksu, involves an extension of cessation of breath that occurs after exhalation and inhalation in rechaka and pūraka that is not determined by time and number, and adept of this stage of prāṇāyāma. One might also suppose that in the state the body is being maintained by the internal circulation of prāṇa rather than any external flow of breath.
The Yoga Sūtras of Patañjali, Prof. Edwin F. Bryant
“The fourth type of prāṇāyāma transcends the external and internal prāṇāmayas, and appears effortless and non-deliberate.”
“The fourth type of prāṇāyāma goes beyond the regulation or modulation of breath flow and retention, transcending the methodology given in the previous sūtra. It is a state similar to kevala kumbhaka, which is mentioned in the haṭhayoga texts and in the yoga upaniṣads.”
“When the movement of the breath functions without one’s volition or effort, the fourth stage of prāṇāyāma has been reached. The movements of the mind and consciousness cease. The flows of vital energy, intelligence and consciousness come to a standstill except for subliminal impressions. This is like virāma pratyaya, as explained in I.18. A state of pause is experienced, in both the breath and the mind. From this springs forth a new awakening and the light of intelligence vigorously penetrates the sādhaka’s innermost being.”
“Since this fourth stage contains no restrictions, it transcends the range of movements described in the prāṇāyāmas of II.50. It is therefore a ‘seedless’ (nirbīja) prāṇāyāma.”
Light on the Yoga Sūtas of Patañjali, B.K.S. Iyengar
II.52 tataḥ kṣīyate prakāśāvaraṇam
Then, the covering of illumination [of knowledge] is weakened.
“Prakāśa, illumination, as we know it from II.18, is a synonym for sattva. The covering of illumination, prakāśa-āvaraṇa, says Vyāsa, is ultimately karma, and this is destroyed by the practice of prāṇāyāma. He quotes a verse that speaks of karma as the ‘net of great illusion’ that covers sattva and impels one to commit immoral deeds. Karma, we recall, consists of actions that are all recorded in the citta as saṁskāras and that fructify at the appropriate time, conditioning one to act in certain ways. Karma is in this sense synonymous with the storehouse of saṁskāras, which trigger the behavioral patterns and preconditioned attitudes, perspectives, or responses to the world, such as the immoral deeds mentioned by Vyāsa.”
The Yoga Sūtras of Patañjali, Prof. Edwin F. Bryant
“Prāṇāyāma removes the veil covering the light of knowledge and heralds the dawn of wisdom.”
“Its practice destroys illusion, consisting of ignorance, desire, and delusion which obscure the intelligence; and allows the inner light of wisdom to shine. As the breeze disperses the clouds that cover the sun, prāṇāyāma wafts away the clouds that hide the light of the intelligence.”
“In the Yoga Chuḍāmaṇi Upaniṣad, it is said that there is no discipline higher than prāṇāyāma. It is called an exalted knowledge (mahāvidyā), a royal road to well-being, freedom and bliss.”
Light on the Yoga Sūtas of Patañjali, B.K.S. Iyengar
II.53 dhāraṇāsu ca yogyatā manasaḥ
Additionally, the mind becomes not for concentration
Manasaḥ is used here rather than citta, as it is the specific aspect of citta that interacts with the senses, and awareness must now make a transition from the sensory involvements of prāṇāyāma and the next limb, pratyāhāra, to the transitory stage of dhāraṇā, concentration. Dhāraṇā is the sixth limb of yoga, which will be discussed shortly. The commentators assume this sūtra to be self-explanatory and have little to add. For the mind to be able to fix on an object of concentration, it must be sattvic, that is rajas and tamas must be minimized.”
The Yoga Sūtras of Patañjali, Prof. Edwin F. Bryant
“Prāṇāyāma is not only an instrument to steady the mind, but also the gateway to concentration, dhāraṇā.”
“Once the new light of knowledge has dawned through the practice of prāṇāyāma, the mind is fit and competent to move on towards the realization of the soul.”
“The implication here is clear that the sādhaka who had to struggle initially to cultivate a yogic way of life by self-discipline and study, now finds his efforts transformed into a natural zeal to proceed in his sādhana.”
Light on the Yoga Sūtas of Patañjali, B.K.S. Iyengar
Rafael Durán 