Srimad Bhagavatam — Shashtha Skandha, Shloka 18
Viśvarūpa’s Death, Vṛtrāsura’s Manifestation, and the Devas’ Surrender to Nārāyaṇa
येनावृता इमे लोकास्तपसा त्वाष्ट्रमूर्तिना । स वै वृत्र इति प्रोक्त: पाप: परमदारुण: ॥ १८ ॥
yenāvṛtā ime lokās tapasā tvāṣṭra-mūrtinā sa vai vṛtra iti proktaḥ pāpaḥ parama-dāruṇaḥ
That most dreadful demon, the son of Tvaṣṭā, by the power of his austerity covered all the worlds; therefore he was called Vṛtra—“the one who covers everything.”
In the Vedas it is said, sa imāḻ lokān āvṛṇot tad vṛtrasya vṛtratvam: because the demon covered all the planetary systems, his name was Vṛtrāsura.
FAQs
Vṛtra is the formidable being born through Tvaṣṭā’s agency, whose immense ascetic power obstructed the worlds; hence he is called “Vṛtra,” the obstructor.
Because by his tapas and power he “covered” or blocked the worlds—creating obstruction—so he is designated Vṛtra, meaning one who restrains or obstructs.
Tapas is powerful and results are real; the verse cautions that strength gained through discipline should be guided by dharma and devotion, otherwise it can become destructive and harmful to others.