Generally the animal, they are meant for sense gratification, but human life has to practice tapasya to control sense gratification. Just like we are prescribing to our disciples—no illicit sex life, no intoxicants, no meat-eating and no gambling. No illicit sex means, just like the dogs and hogs, they have no consideration with whom they're having sex intercourse. The hog especially, pig, he does not discriminate whether sister, mother or anyone, you see. So tapaḥ means . . . we are accustomed to so many, I mean to say, sinful activities, so we have to restrain from them. So tapasya, accepting voluntarily some painful situation, that is required. Say for (example) I am accustomed to smoke or to drink wine. So I have to give it up. This is meant for human life. I have to give it up. Although I shall feel some pain in the beginning, but still I have to tolerate it. This is called tapasya.
In the Western countries, to give up these habit is little difficult. Because about forty years ago, one of my brother, Godbrother, came to London, and he had a talk with Marquis of Zetland, and the Lord inquired from him whether he can be converted into a brāhmaṇa. He inquired from my Godbrother whether he can be made into a brāhmaṇa. Brāhmaṇa. So our Godbrother said: "Yes, you can be converted into a brāhmaṇa if you give up these habits, namely illicit sex, intoxication, meat-eating and gambling." The gentleman's reply, Lord Zetland: "It is impossible." So that means he was not prepared to accept the tapasya, voluntarily abnegation.
But here Ṛṣabhadeva says that the human life is meant for tapasya, and not for living like pigs, hogs and dogs. Next He says, tapo divyam (SB 5.5.1), because tapasya means to accept voluntarily some painful situation. It is not very much painful, but they consider. But we are undergoing already some painful situation working day and night. To satisfy the senses, that also requires tapasya, hard labor. But here Ṛṣabhadeva says that you accept some painful condition—it is not at all painful, but it appears—tapo divyam, for God realization. (break) . . . that everyone is working hard day and night, but that is for sense gratification. Similarly, if you take little trouble, if you accept voluntarily some painful condition for realizing God, divyam, that is the human mission.
Now the question may be raised that both ways, I have to accept some painful situation, so why shall I accept painful situation for realizing God? For material sense gratification, although I am working very hard, I am getting, immediately, some pleasure, sense pleasure. So why shall I work hard or accept some painful situation for realizing God, which is unknown and fictitious to me? So the reply is, tapo divyaṁ putrakā yena śuddhyed sattvam (SB 5.5.1): "My dear boys, if you accept a little trouble for realizing God, then your existentional condition will be purified." But what is the use of purifying? There is need. If you purify, purify yourself, existentional condition, then you will be saved from the four kinds of troubles or miseries of life, namely birth, death, old age and disease.