Everything is described in the Bhagavad-gītā. Bhagavad-gītā does not say that "You live by breathing air." No. Bhagavad-gītā says, annād bhavanti bhūtāni (BG 3.14). Anna. Anna means food grains. There is necessity of food grain. Annād bhavanti bhūtāni. Bhagavad-gītā never says that "you don't require to eat. You simply breathe air and practice yoga." No. But we must eat neither more, nor less. That is recommended. Yuktāhāra-vihārasya. We should not eat more, nor less. And nirāśīḥ. Nirāśīḥ means desireless of extravagance. Now we are desiring for sense gratification more and more. That is not wanted. If you want perfection of life.... This is called tapasya.
One has got the desire, but he should not desire unnecessarily. Everyone has got the right to eat, even the animals. Everyone has got the right. But because we are desiring to enjoy more, therefore we do not give the chance to the animals to live properly; rather, we are trying to eat the animals. This is not required. This is called nirāśīḥ. Why you should eat animals? That is uncivilized life. When there is no food, when they are aborigines, they may eat animals, because they do not know how to grow food. But when the human society becomes civilized, he can grow so many nice foods, he can keep the cows, instead of eating the cows. He can get milk, sufficient milk. We can make so many preparation from milk and grains. So we should not desire unnecessarily to enjoy more.
Then it is said here, kurvan nāpnoti kilbiṣam (BG 4.21). Kilbiṣam means resultant action of sinful life. Kilbiṣam. So if we don't desire more than our necessary, then we are not implicated, involved in sinful activity, kurvan api, even though he is engaged in working. While you are working, knowingly or unknowingly, you have to commit something which is not pious, even sinful, but if you simply desire for living properly, then kurvan nāpnoti kilbiṣam. Our life should be without any sinful reaction. Otherwise we will have to suffer. But they do not believe, although they are seeing so many abominable lives. Wherefrom they are coming, 8,400,000 species of life? There are so many lives living very abominable condition. Of course, the animal or the living creature does not know, but we human being, we should know why this abominable life. It is māyā's illusion.
Even one is.... Just like a pig is living in a very filthy condition, eating stool, and still, he is thinking very happy, and therefore he is getting fat. When one feels happy, "I am very happy," he becomes fatty. So you will find these pigs, they are very much fatty, but what they eat? They eat stool and live in a filthy place. But they think that "We are very happy." So that is māyā's illusion. Anyone who is living in a very abominable condition of life, māyā, by illusion, he is thinking that he is all right, he is living very perfectly. But a person who is on the higher stage, he sees that he is living in a very abominable condition.
So this illusion is there, but by knowledge, by good association, by taking instruction from the śāstra, from guru, from saintly persons, one should understand what is the value of life and live like that. So this is instructed by Kṛṣṇa, that nirāśīḥ, one should not be unnecessarily desireful, more than his necessities of life. This is called nirāśīḥ. Nirāśīḥ. Another meaning is that not very much fond of material enjoyment. And that is possible when he is in full knowledge that "I am not this body. I am spirit soul. My necessity is how to advance in spiritual knowledge." Then he can become nirāśīḥ. These are the items for tapasya, austerity, penance.
People have forgotten now. They do not know what is the austerities. But the human life is meant for that purpose. Tapo divyaṁ putrakā yena śuddhyet sattvaṁ yena brahma-saukhyam anantam (SB 5.5.1). These are the instruction of the śāstra. The human life is meant for tapasya. And tapasya...
Therefore in the Vedic way of life the beginning of life is tapasya, brahmacārī, brahmacārī. A student is sent to gurukula for practicing brahmacarya. This is tapasya, not comfortable life. Lying down on the floor, going door-to-door for begging alms for guru. But they are not tired. Because they are children, if they are trained these austerities, they become to practice. They call all woman, "Mother." "Mother, give me some alms." And they come back to guru's place. Everything belongs to guru. This brahmacārī life. This is tapasya. Tapo divyam (SB 5.5.1). That is Vedic civilization, that children should be from the very beginning of life trained up in tapasya, brahmacarya. Celibacy. A brahmacārī cannot see any young woman. Even the guru's wife is young, he cannot go to the guru's wife. These are the restriction. Now where is that brahmacarya? No brahmacārī. This is Kali-yuga. No tapasya.