मूढग्राहेणात्मनो यत्पीडया क्रियते तपः | परस्योत्सादनार्थं वा तत्तामसमुदाहृतम् ||
mūḍha-grāheṇātmano yat pīḍayā kriyate tapaḥ parasyotsādanārthaṁ vā tat tāmasam udāhṛtam
Translation
Austerity performed out of foolish notions, with self-torture, or for the purpose of harming others — that is declared to be tamasic.
Interpretation
Tamasic tapas: performed out of foolish stubbornness (mudha-graha — holding onto a deluded view), involving genuine self-torture (atmanah pidaya — causing oneself real suffering), or motivated by the desire to harm others (parasyotsadanartham — for the purpose of undermining or destroying others). This last category is particularly dark: austerities performed to generate spiritual power in order to harm enemies — black magic, curses, destructive practices. All three forms of tamasic tapas emerge from darkness and produce darkness. They create suffering without producing wisdom, and bind rather than liberate.