By His Divine Grace A. C. Bhaktivedanta Swami Prabhupāda
A man or woman who indulges in sexual intercourse with an unworthy member of the opposite sex is punished after death by the assistants of Yamarāja in the hell known as Taptasūrmi. There such men and women are beaten with whips. The man is forced to embrace a red-hot iron form of a woman, and the woman is forced to embrace a similar form of a man. Such is the punishment for illicit sex. (SB 5.26.20)
Generally a man should not have sexual relations with any woman other than his wife. According to Vedic principles, the wife of another man is considered one’s mother, and sexual relations are strictly forbidden with one’s mother, sister and daughter. If one indulges in illicit sexual relations with another man’s wife, that activity is considered identical with having sex with one’s mother. This act is most sinful. The same principle holds for a woman also; if she enjoys sex with a man other than her husband, the act is tantamount to having sexual relations with her father or son. Illicit sex life is always forbidden, and any man or woman who indulges in it is punished in the manner described in this verse.
A person who indulges in sex indiscriminately—even with animals—is taken after death to the hell known as Vajrakantaka-śālmalī. In this hell there is a silk-cotton tree full of thorns as strong as thunderbolts. The agents of Yamarāja hang the sinful man on that tree and pull him down forcibly so that the thorns very severely tear his body. (SB 5.26.21)
The sexual urge is so strong that sometimes a man indulges in sexual relations with a cow, or a woman indulges in sexual relations with a dog. Such men and women are put into the hell known as Vajrakantaka-śālmalī. The Krishna consciousness movement forbids illicit sex. From the description of these verses, we can understand what an extremely sinful act illicit sex is. Sometimes people disbelieve these descriptions of hell, but whether one believes or not, everything must be carried out by the laws of nature, which no one can avoid.
A person who is born into a responsible family—such as a kshatriya, a member of royalty or a government servant—but who neglects to execute his prescribed duties according to religious principles, and who thus becomes degraded, falls down at the time of death into the river of hell known as Vaitarani. This river, which is a moat surrounding hell, is full of ferocious aquatic animals. When a sinful man is thrown into the River Vaitarani, the aquatic animals there immediately begin to eat him, but because of his extremely sinful life, he does not leave his body. He constantly remembers his sinful activities and suffers terribly in that river, which is full of stool, urine, pus, blood, hair, nails, bones, marrow, flesh and fat. (SB 5.26.22)
The shameless husbands of lowborn śūdra women live exactly like animals, and therefore they have no good behavior, cleanliness or regulated life. After death, such persons are thrown into the hell called Pūyoda, where they are put into an ocean filled with pus, stool, urine, mucus, saliva and similar things. Śūdras who could not improve themselves fall into that ocean and are forced to eat those disgusting things. (SB 5.26.23)
Śrīla Narottama dāsa Thākura has sung,
karma-kānda, jnāna-kānda, kevala vishera bānda,
amrta baliyā yebā khāya
nānā yoni sadā phire, kadarya bhakshana kare,
tāra janma adah-pate yāya
He says that persons following the paths of karma-kānda and jnāna-kānda (fruitive activities and speculative thinking) are missing the opportunities for human birth and gliding down into the cycle of birth and death. Thus there is always the chance that he may be put into the Pūyoda Naraka, the hell named Pūyoda, where one is forced to eat stool, urine, pus, mucus, saliva and other abominable things. It is significant that this verse is spoken especially about śūdras. If one is born a śūdra, he must continually return to the ocean of Pūyoda to eat horrible things. Thus even a born śūdra is expected to become a brāhmana; that is the meaning of human life. Everyone should improve himself. Krishna says in Bhagavad-gita (4.13), cātur-varnyam mayā srishtam guna-karma-vibhāgaśah: “According to the three modes of material nature and the work ascribed to them, four divisions of human society were created by Me.” Even if one is by qualification a śūdra, he must try to improve his position and become a brāhmana. No one should try to check a person, no matter what his present position is, from coming to the platform of a brāhmana or a Vaishnava. Actually, one must come to the platform of a Vaishnava. Then he automatically becomes a brāhmana.
This can be done only if the Krishna consciousness movement is spread, for we are trying to elevate everyone to the platform of Vaishnava. As Krishna says in Bhagavad-gita (18.66), sarva-dharmān parityajya mām ekam śaranam vraja: “Abandon all other duties and simply surrender unto Me.” One must give up the occupational duties of a śūdra, kshatriya or vaiśya and adopt the occupational duties of a Vaishnava, which include the activities of a brāhmana. Krishna explains this in Bhagavad-gita (9.32):
mām hi pārtha vyapāśritya ye ‘pi syuh pāpa-yonayah
striyo vaiśyās tathā śūdrās te ‘pi yānti parām gatim
“O son of Prtha, those who take shelter in Me, though they be of lower birth—women, vaiśyas [merchants], as well as śūdras [workers]—can approach the supreme destination.”
Human life is specifically meant for going back home, back to Godhead. That facility should be given to everyone, whether one be a śūdra, a vaiśya, a woman or a kshatriya. This is the purpose of the Krishna consciousness movement. However, if one is satisfied to remain a śūdra, he must suffer as described in this verse: tad evātibībhatsitam aśnanti.
[Bhaktivedanta Purports to verse 20-23, Chapter Twenty Six, Canto Five of the Srimad Bhagavatam]