Canto 3 -
Araṇya-kāṇḍa
Chapter 48: Sītā-devī Condemns Rāvaṇa
Text 3.48.4

येन वैश्रवणो राजा द्वैमात्रः कारणान्तरे।
द्वन्द्वमासादितः क्रोधाद्रणे विक्रम्य निर्जितः॥

yena vaiśravaṇo rājā dvaimātraḥ kāraṇāntare
dvandvam āsāditaḥ krodhād raṇe vikramya nirjitaḥ

yena = me; vaiśravaṇaḥ = Vaiśravaṇa; rājā = King; dvaimātraḥ = my stepbrother; kāraṇa-antare = For some reason; dvandvam āsāditaḥ = had to face in battle 1; krodhāt = in a fit of anger; raṇe = in battle; vikramya = I fought with him; nirjitaḥ = and conquered him.

For some reason King Vaiśravaṇa, my stepbrother, had to face me in battle. In a fit of anger, I fought with him and conquered him in battle.

GLOSS. “For some reason” means “Because I followed the instructions of my mother.”