BG 17.5
अशास्त्रविहितं घोरं तप्यन्ते ये तपो जनाः
दम्भाहंकारसंयुक्ताः कामरागबलान्विताः
aśāstravihitaṃ ghoraṃ tapyante ye tapo janāḥ
dambhāhaṃkārasaṃyuktāḥ kāmarāgabalānvitāḥ
TRANSLATION
Those men who practise terrible austerity not enjoined by the Shastras, given to ostentation and conceit, and prompted by the force of sensual desires and passion;