Preamble

After describing the Knowledge sacrifice and the faculty of  seeing everything as Brahman the Lord proceeds to enumerate other kinds of  sacrifices (Yajnas) and extols the Knowledge sacrifice as the highest. When a  seeker constantly practices the different types of Yajnas suggested in this section  he gains wisdom. With the dawn of wisdom he begins to develop renunciation and  perceives the identity of the atman and brahman.

Yajna in the ancient past merely meant the ritual of  fire worship by kindling the flames with the offerings therein by the people. Krishna gives a new interpretation to the word Yajna to mean  the conversion of human day to day activities into worship. The cycle of human activity  starts with the receipt of stimuli from the world at large by the organs of perception,  which turn them into reaction in mind and intellect, and which are returned as  a response back into the world through the organs of action. This entire cycle  has been split into twelve main activities; each of them turned into a ritual,  worship, a Yajna. Those who understand this and turn their daily activities into  a practice of these yajnas will free themselves from the vasanas / desires.

This  concept of viewing daily activities as a Yajna can be further explained in  simpler terms. Take for instance the most common activities of eating and  reading. This can be stated in the Gita language as “People offer  the sense of hunger as sacrifice in the fire of food; others offer the sense of  ignorance as sacrifice in the fire of the knowledge” What does this mean?  It simply means that food satisfies hunger or hunger is burnt in the Yajnakund of food or hunger is burnt by food or just hunger is satiated by consuming  food. Similarly, knowledge removes ignorance or ignorance is burnt in the  sacrificial fire of knowledge or ignorance is burnt (removed) by knowledge or  just ignorance disappears when knowledge dawns.

By converting activities into Yajna (worship) a  seeker drops his vasanas and gradually gains knowledge of the Self. The supermost  of all yajnas is jnana yajna,  the yajna of Wisdom. A seeker should prepare himself for the yajna through devotion,  enquiry and service. With such preparation he will attract a perfect Guru to  teach him the knowledge of the Self. This knowledge of the Self destroys all  desires and agitations and removes forever his delusion that the world is real.

The knowledge of Self purifies the mind of all  agitations and gives supreme Peace. Those devoted to Self control their senses  and pursue the Self with consistency until they reach it. The ignorant, ever  doubtful of the Self, lack steadiness of purpose. They will not achieve  anything in this world or the next nor will they find any enduring happiness. Krishna, therefore, advises Arjuna to gain knowledge and  remove all doubts and delusion and thus become established in the Supreme Self. 

The Text

daivamevaapare yajnam yoginah paryupaasate
    brahmaagnaavapare yajnam yajnenaivopajuhwati // 4.25 //

Some Yogis offer oblations or perform  sacrifice to Devas alone (Deva-yagna); while others offer the Self as sacrifice  by the Self into the fire of Brahman (Brahma Yagna).

Sri Krishna explains the mental  attitude of a sage when he comes in contact with the world and functions in it.  The Lord is enumerating in these verses twelve different types of Yagnas, each  one apparently meaning ritualism but in fact suggesting different patterns of  life wherein by the necessary adjustments in the mind we can effectively change  the entire reactions of the world upon us.

Deva Yagna - Some Yogis perform sacrifice to Devas alone: According  to ritualism this means invoking the grace of a specific deity and offering  oblations to it in the sacred fire for gaining its blessings.  But here it means that the perfect masters  (Yogis) when they move in the world do perceive objects but their understanding  and experience of the perception is of such a nature that the world of objects  was subservient to the five sense organs which are Devas.  When this mental attitude is entertained by  the seeker, he feels detached from the sense experience and is able to have a  sense of inner equanimity. It is surrendering individual consciousness to  Cosmic Consciousness.

Brahma Yagna - Offering the Self as a sacrifice by the Self in the  fire of Brahman: The outer world by itself is incapable of giving us sorrow or joy;  but it is our attitude towards the objects and situations of the outer world  that brings us such feelings. The perfect masters understand that the sense  organs are mere instruments of perception and tune them to sacrifice themselves  in the knowledge of the Brahman. When an individual's organs of perception and  action are to function not for satisfying his selfish needs but for the sake of  serving the society at large, then although he lives in the world of objects he  will not have any attachment to them.

The limiting accessories such as  body, mind and intellect which are super imposed on the Self through ignorance  are subordinated and the identity of the individual soul with the Supreme Soul  is realized. The offering of the Self in the Brahman is to know that the Self  which is associated with the limiting adjuncts is identical with the  unconditioned Supreme Brahman. This is called Brahma Yagna wherein the Self is  divested of Its Upadhis or limiting adjuncts so that it is recognized as the  Supreme Self or Brahman.

Brahman is described in the  scriptures as Consciousness, Knowledge and Bliss and as the innermost Self of  all. It is devoid of all limitations imposed by time, space and causality. The  individual self is in reality Brahman, but appears as the individual through  association with the body, mind, intelligence and senses. To know the  conditioned self as one with the unconditioned Brahman is to sacrifice the self  in the fire of Brahman. This sacrifice is performed by those who have renounced  all action and are devoted to the Knowledge of Brahman.
    shrotraadeeneendriyaanyanye samyamaagnishu juhwati
    shabdaadeen vishayaananya indriyaagnishu juhwati  // 4.26 //

Some again offer hearing and  other senses as sacrifice in the fire of restraint; others offer sound and  other objects of the senses as sacrifice in the fire of the senses.

To offer hearing and other senses  in the fire of restraint: Some masters live constantly offering the senses into  the fire of self-control so that the senses, of their own accord, get burnt up  giving them inner joy. The more we satisfy the sense organs, the more they demand  and this process goes on endlessly. Hence self-control of the sense organs is  the only way to tame them for experiencing inner peace. This is the path of  self control which is also an act of Yagna. Every form of self control, where  we surrender the egocentric enjoyment for the higher delight, where we give up  lower impulses, is said to be a sacrifice.

To offer sound and other objects  of sense in the fire of the senses : Others direct their senses towards pure  and unforbidden objects of the senses and in so doing regard themselves as  performing acts of sacrifice. Under this method the senses are made the best  use of for the adoration of the Almighty.   In the fire of the senses, sense objects are offered as oblation. The  sensual is transformed into spiritual.

Two diametrically opposite types  of Yagnas are mentioned here. One makes the senses ineffective and the other  makes the senses super-effective. The method of self control is negative (which  is given to the few) while sense-sublimation is positive (which is given to the  aspiring many); but both achieve the same objective i.e. purification of the  mind.

sarvaaneendriya karmaani praanakarmaani chaapare
    aatmasamyamayogaagnau juhwati jnaanadeepite  // 4.27 //

Others again sacrifice all the  functions of the senses and the functions of the breath (vital energy) in the  fire of the Yoga of self-restraint kindled by knowledge.

Control of the ego by better  understanding of the Divine behind it is called atma-samyama-yoga i.e.  the Yoga of self-restraint. All the activities of sense organs and the organs  of action as well as the objects of the senses together with the functions of  the prana are offered into the knowledge-kindled fire of right  understanding i.e. meditation which is one-pointed discriminative wisdom. The  idea conveyed here is that by stopping all activities, the masters concentrate  the mind on the Self.