᠑5᠑
Bhagavad-णोंवे  As It les
[Ch. 4]
long as the soul is attached to sense enjoyment, it is called  parag-ātmā . The soul is subjected to the functions of ten kinds of air at work within the body, and this is perceived through the breathing system. The Pātañjala system of  yoga  instructs one on how to control the functions of the body's air in a technical manner so that ultimately all the functions of the air within become favorable for purifying the soul of material attachment. According to this  yoga  system,  pratyag ātmā  is the ultimate goal. This  pratyag ātmā  is a withdrawal from activities in matter. The senses interact with the sense objects, like the ear for hearing, eyes for seeing, nose for smelling, tongue for tasting, hand for touching, and all of them are thus engaged in activities outside the self. They are called the functions of the  prāṇa-vāyu . The  apāna-vāyu  goes downwards,  vyāna-vāyu  acts to shrink and expand,  samāna-vāyu  adjusts equilibrium,  udāna-vāyu  goes upwards—and when one is enlightened, one engages all these in searching for self-realization.
TEXT 28
द्रव्ययज्ञास्तपोयज्ञा योगयज्ञास्तथापरे । 
    स्वाध्यायज्ञानयज्ञाश्च यतयः संशितत्रताः ॥२८॥
dravya-yajñās tapo-yajñā yoga-yajñās tathāpare svādhyāya-jñāna-yajñāś ca yatayaḥ saṁśita-vratāḥ
dravya-yajñāḥ —sacrificing one’s possessions;  tapo-yajñāḥ —sacrifice in austerities;  yoga-yajñāḥ —sacrifice in eightfold mysticism;  tathā —thus;  apare —others;  svādhyāya —sacrifice in the study of the  Vedas ;  jñāna-yajñāḥ —sacrifice in advancement of transcendental knowledge;  ca —also;  yatayaḥ —enlightened;  saṁśita —taken to strict;  vratāḥ —vows.
TRANSLATION
There are others who, enlightened by sacrificing their material possessions in severe austerities, take strict vows and practice the yoga of eightfold mysticism, and others study the Vedas for the advancement of transcendental knowledge.