The entire content of this mail is from Shri V N Gopala Desikan's Srimad Bhagavad Gita, published by Vishishtadvaita Research Centre, Chennai and The Bhagavad Gita by Swami Chidbhavananda published by Ramakrishna Mission
The Three Fold Austerity 14-19
1 Gita Sloka Every Day - Chapter 17 - Shraddhatraya Vibhaga Yoga - Sloka 19
Mudha grahena atmanah yat peedhaya kriyate tapah I
Parasya ud sadana arthamva tat tamasam udahrutam II sloka 19
मूढा ग्राहेण आत्मनः यत् पीढया क्रियते तपः I
परस्य उद् सादना अर्थंव तत् तामसं उदह्रुतम् II श्लोक 19
That austerity which is practised with foolish obstinacy, self torture or for the purpose of destroying another, is declared as tamasika.
Among human beings there are individuals resembling stones and blocks. Their intellectual development is yet incomplete. ideals in life are imperfectly understood by them. Such dullards also take to the practise of austerity without knowing its scope. They fast to the point of self -immolation, expose themselves to the heat of the sun and fire and dip themselves into the cold water to benumb their senses. They are body centred and torture it religiously. Occasionally they stumble upon some psychic power which they utilise for hurting, wrecking and destroying others These men are tamasika in the performance of their austerity