The Great Epic of the Bhārata dynasty 6.39.5

6.39.5

aśāstravihitaṃ ghoraṃ tapyante ye tapo janāḥ |
dambhāhaṃkārasaṃyuktāḥ kāmarāgabalānvitāḥ || 5 ||

Those men who practise severe austerities not enjoined by the Shâstras, given to ostentation and egoism, possessed with the power of lust and attachment, torture, senseless as they are, all the organs in the body, and Me dwelling in the body within; know them to be of Asurika resolve.