कर्षयन्तः शरीरस्थं भूतग्राममचेतसः।
मां चैवान्तःशरीरस्थं तान्विद्ध्यासुरनिश्चयान्।।17.6।।
17.6. Who emaciate unintelligently the conglamoration of elements in their physic and emaciate Me too, dwelling within the physic-know them to be of a demoniac resolve.
17.4-6 Yajante etc., upto asura-niscayan. Unintelligently : i.e. due to their lack of discrimination. Emaciating Me too : Because they do not follow the purport of the scriptures. That is why they undertake practising austerities invented by their own intellect and they are rather men of the Tamas (Strand). Like faith, the food also is of three types, differentiated by the Sattva etc., so are the sacrifice, austerity and charity. That is being detailed as :
Karshayantah shareerastham bhootagraamamachetasah; Maam chaivaantahshareerastham taanviddhyaasuranishchayaan.
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