Shloka 3.32.17
अरण्यकाण्डे द्वात्रिंशः सर्गः — Śūrpaṇakhā’s Report to Rāvaṇa and the Panegyric of His Might
दशवर्षसहस्राणि तपस्तप्वा महावने।पुरा स्वयंभुवे धीरश्शिरांस्युपजहार यः।।।।
daśavarṣasahasrāṇi tapas taptvā mahāvane |
purā svayaṃbhuve dhīraḥ śirāṃsy upajahāra yaḥ ||
Steadfast, he once performed tapas for ten thousand years in a great forest, and offered up his own heads to Svayaṃbhū (Brahmā).
This steadfast Ravana who had in the past performed penance for ten thousand years in a dense forest offered his heads to the self-born Brahma.
Tapas (austerity) is spiritually potent, but Dharma requires that such power be governed by right intention and welfare of beings. The Ramayana repeatedly shows that spiritual attainments without ethical restraint can become instruments of adharma.
The narration highlights Rāvaṇa’s past austerities and extreme offerings to Brahmā, explaining the source of his boons and consequent fearlessness.
Resolve and endurance (dhairya) in austerity—though later contrasted with moral failure, showing that discipline alone is not the same as righteousness.