Sanskrit
मूढग्राहेणात्मनो यत्पीडया क्रियते तपः । परस्योत्सादनार्थं वा तत्तामसमुदाहृतम् ॥
mūḍhagrāheṇātmano yat pīḍayā kriyate tapaḥ parasyotsādanārthaṃ vā tat tāmasam udāhṛtam
Translation
That austerity done under a deluded understanding, with self-torture, or with the object of destroying another, that is declared of darkness.
Annie Besant · The Bhagavad-Gita, translated by Annie Besant (4th ed., 1922) — Wikisource · Public Domain
Explanation
The tamasic verdict closes the loop back to verses 5-6: austerity driven by delusion, self-torture, or the outright intent to harm someone else is the same failure mode named at the chapter’s opening, now formally slotted into the threefold grade. It’s a text taking a real, still-current problem seriously — the use of ascetic or spiritual discipline as a cover for self-harm or malice — rather than treating all renunciation as automatically virtuous.