Shloka 3.48.21
रावणस्यात्मप्रशंसा लङ्कावर्णनं च — Ravana’s Self-Praise and the Description of Lanka
कथं वैश्रवणं देवं सर्वभूतनमस्कृतम्।भ्रातरं व्यपदिश्य त्वमशुभं कर्तुमिच्छसि।।।।
yena vaiśravaṇo rājā dvaimātraḥ kāraṇāntare |
dvandvam āsāditaḥ krodhād raṇe vikramya nirjitaḥ ||
He claims that, for some other cause, he challenged King Vaiśravaṇa (Kubera), born of a different mother, and in anger defeated him in single combat through prowess in battle.
Why do you wish to do something inauspicious by calling Lord Kubera who is worshipped by all beings your brother ?
It warns against boasting of aggression and anger-driven conflict; Dharma restrains krodha (anger) and rejects glory built on injustice.
Rāvaṇa tries to impress and intimidate Sītā by recounting his victory over Kubera.
Sītā’s discernment is implied—she evaluates power through righteousness, not mere conquest.