This verse speaks of the sin involved in not performing the sacrifice. He who does not partake of the instituted cycle moving from beginning to end—from yajña to rain; from rain to food; from food to nourishment of men; from men to performance of yajña; from yajña to rain—he who does not institute the cycle by performance of yajña—leads a life full of sin. [Note: The cycle is as follows: Supreme Lord, Vedas, action, sacrifice, rain, food, and production of living entities. The new living entities then study the Vedas arising from the Lord, perform action, and sacrifice (with the Lord present within) again. At the same time as fulfilling ones material needs by sacrifice one can attain the Lord. Rāmānuja takes brahman as the body and akṣara as the soul, which is necessary for the body to function. Then the cycle is: soul in the body, action, sacrifice, rain, food, nourishment of the body with a soul (bhutāni); then action, sacrifice etc. Madhva takes brahman as the Lord and akṣara as the Vedas. Vedas reveal the Lord, the Lord inspires prescribed action, then sacrifice, rain, food, nourishment of bodies, study of Vedas, revelation of the Lord, inspiration to action etc.] Who will not sink to hell?

This verse speaks of the fault in not performing sacrifice. From the Lord arose the Vedas. From the Vedas arose sacrifice. [Note: According to the sequence in the verses, from the Vedas arises prescribed actions, and from actions comes sacrifice.] From sacrifice comes rain, and from rain comes food. From the food comes living beings. From the living beings again comes prescribed action. He who does not follow this cycle as described above (evam) which supports the whole universe, inaugurated by the Supreme Lord (pravartitam), the protector of the progeny—that person who ignores the Lord, that person whose life is thus sinful (aghāyuḥ), lives completely in vain (mogham), O son of Pṛthā, because that person enjoys sense objects with his senses, instead of the remnants of the sacrifice approved by the Lord.

Is life is useless and and is going to be down.

Explanation from a different angle how this karma‑kanda changes to karma‑yoga: When one performs sacrifice he understands that instead of getting his sense gratification now, he can rather go to "svarga" and enjoy millions of times more; and then by associating with the brahmanas‑priests (who have the business of giving people proper knowledge) they come to realize that in this material world there is no place to enjoy ‑ because everywhere there is birth and death. Gradually one gets higher and higher realizations by performing his prescribed duties he surrenders to authority (2) he hears about sense enjoyment from the brahmanas‑ priests, (3) he hears about the Vedas from these brahmanas and thus his faith becomes established in the Vedas and in the brahmanas because they give him what he wa and (4) as he is getting faith in the Vedas and brahmanas, he is also hearing them about other things such as "svargaloka", better things, and he thinks: "yes this is more wonderful!", and then (5) also as one tries to enjoy in this material world, the more one sees that there are so many problems ( one's mother dies, one's sons dies, there are so many natural catastrophes, etc, etc., even in svarga, Indra is always afraid of the de so he will also be afraid of demons.) (6)Gradually he is getting all this transcendental knowledge and he experiences tha material world doesn't bring the satisfaction even though he has these desires and his desires have been fulfilled. Still he is not feeling satisfied in his heart and gradually after hearing the 96,000 laks of vedic karma‑kanda version, after naturally, he also hears the 4,000 of laks of jnana‑kanda verses and he hears that he is not his body, and he is becoming more receptive to it because he is more familiar with the system. He trusts the priests he trusts the sastras he gradually becomes detached due to all these and his acceptance of authority is higher and he is gradually getting transcendental knowledge and detachment and more and more. That's basically how the system works. This is indicated here in the Bhagavad‑gita in codified form in this Section "From karma‑kanda to karma‑yoga". When one actually establishes that: "my goal is getting out of this world", then karma‑kanda becomes karma‑yoga. Yoga meaning linking with the Supreme. But still he has material desires. Just establishing himself "wanting to get out of this material world" doesn't free him, but he is established on the process starting with sakama karma‑yoga, with material desires, and gradually he is going to go up to the next stage which already has been described, of working, doing one's duty, with detachment because he already has transcendental knowledge ‑ that is niskama karma‑yoga or buddhi‑yoga which is a combination of karma and jnana. If one performs his karma properly, according to the Vedas, it naturally leads to jnana. One keeps on doing his karma but on the shade of jnana ‑ that is called niskama karma. There are two more sections in this Chapter. The next, Section D is "Niskama karma, act dutifully with detachment to set the correct example". Because the question may be raised: prescribed duties are meant to get your material rewards, "but now by your mercy, my dear brahmanas‑priests, by the mercy of the devotees I have no longer any material desires, I don't want a son or money, or a nice house, or do I want to go to svarga‑loka, now I have knowledge that I am not my body so therefore I don't have anymore material desires, therefore I don't have to do my prescribed duties anymore. " No! Krsna now is going to explain why, even though one may not have material desires, he should do his prescribed duties on the platform of the self. That is "niskama karma, to set the correct example". (3.17‑32). And finally the great danger will be described. Although one may be very detached from everything still because one has a material body one must be very, very wary of two different things. That is the last Section called "Beware of lust and anger". That will bring one from the jnana platform right down to lowest platform possible.

(REVIEW: Arjuna in the beginning of this Chapter, asked a question which shows that he didn't understand the essence of Chapter 2. In his question he thought that knowledge and work are in oposition with each other he couldn't understand how one could do work in knowledge and therefore be free from any reaction to his work. Knowledge meant to him, (at least in those early chapters) giving up of one's duty specially that duty of fighting in a ghastly warfare. Krsna then explained niskama karma, which was combining jnana with karma and coming up with work which was detached from its fruits. This was Section B. In Section C Krsna explained the system for making society advanced through the Vedic culture, starting with karma‑kanda where someone is attached to the fruits of his work, and by surrender to the Vedic system one becomes detached because he gets transcendental knowledge. And then one is ready to perform work on the niskama karma level where one works but he is detached from the results. Text 16 says: "My dear Arjuna, one who does not follow in human life, the cycle of sacrifice thus established by the Vedas certainly leads a life full of sin. Living only for the satisfaction of the senses, such a person lives in vain." When one has knowledge one has no impetus to perform activities which lead to the gratification of his senses because he knows that he is not the body and therefore he is not interessed in sense gratification. Therefore he will not want to perform his vedic duties. And practically speaking, since the purpose of vedic duties is to bring him to the platform of knowledge, he has no reason to perform his duties because he has achieved the result of those duties ‑ he has already knowledge.

[ D . NISKAMA KARMA. ACT DUTIFULLY WITH DETACHMENT TO SET THE CORRECT EXAMPLE (3.17‑32) 1 . But it is better if one, as did King Janaka and as does Krsna, performs his duties without fruitive desires or attachments. One should act in this way to set the correct example for others. (17‑25)