अशास्त्रविहितं घोरं तप्यन्ते ये तपो जनाः।
दम्भाहङ्कारसंयुक्ताः कामरागबलान्विताः।।17.5।।
17.5 Those persons who, given to ostentation and pride, and possessed of passion, attachment and strength, undertake severe austerities not sanctioned in the scriptures;
17.5 - 17.6 Those men who perform terrible pernances not enjoined by the Sastras - this is illustrative of sacrifices etc., of a similar nature. Those who perform sacrifices, etc., sacrifices which are not enjoined by the Sastras and demand much exertion, those who are possessed of ostentation and conceit and are goaded by sensual desire, attachment and passion - they torture the group of elements such as earth etc., in their bodies. They also torture the individual self which is a part of Myself and is within their bodies. Those who perform such sacrifices etc., know them to be demoniacal in their resolves. The resolve of demons is demoniac resolve. The demons are those who act contrary to My ?ndments. Since they act contrary to My ?ndments, they do not have even a iota of joy, but as stated earlier, they fall a prey to a multitude of calamities. They fall into a foul Naraka (16.16). Now, Sri Krsna, resuming the subject, details the differences according to the Gunas with reference to sacrifice, etc., enjoined by the Sastras. To begin with, he describes three kinds of food, since the growth of Sattva etc., has its source in food, as Srutis declare thus: For my dear, the mind consists of food (Cha. U., 6.5.4) and when the food is pure, the man becomes pure (Cha. U., 7.26.2).
Ashaastravihitam ghoram tapyante ye tapo janaah; Dambhaahamkaarasamyuktaah kaamaraagabalaanvitaah.
aśhāstra-vihitam—not enjoined by the scriptures; ghoram—stern; tapyante—perform; ye—who; tapaḥ—austerities; janāḥ—people; dambha—hypocrisy; ahankāra—egotism; sanyuktāḥ—possessed of; kāma—desire; rāga—attachment; bala—force; anvitāḥ—impelled by; karṣhayantaḥ—torment; śharīra-stham—within the body; bhūta-grāmam—elements of the body; achetasaḥ—senseless; mām—me; cha—and; eva—even; antaḥ—within; śharīra-stham—dwelling in the body; tān—them; viddhi—know; āsura-niśhchayān—of demoniacal resolves