pīḍayā kriyate tapaḥ
tat tāmasam udāhṛtam
mūḍha — foolish; grāheṇa — with endeavor; ātmanaḥ — of one’s own self; yat — which; pīḍayā — by torture; kriyate — is performed; tapaḥ — penance; parasya — to others; utsādana-artham — for the sake of causing annihilation; vā — or; tat — that; tāmasam — in the mode of darkness; udāhṛtam — is said to be.
Penance performed out of foolishness, with self-torture or to destroy or injure others, is said to be in the mode of ignorance.
. . .
मूढग्राहेणात्मनो यत्पीडया क्रियते तप: ।
परस्योत्सादनार्थं वा तत्तामसमुदाहृतम् ॥ १९ ॥