Valmiki Ramayana Yuddha Kanda Sarga 10 Shloka 7
Original Shlokaतंमहाभ्रमिवाऽदित्यस्तेजोविस्तृतरश्मिमान् । अग्रजस्यालयंवीरःप्रविवेशमहाद्युतिः ।।6.10.7।।
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महाद्युतिः one of exceptional splendour, वीरः heroic, तेजो: brilliant विस्तृतरश्मिमान् one whose radiance was spread widely, आदित्यः Sun, महाभ्रमिव: highly lustrous, अग्रजस्य: brother's, तम् आलयम् that abode, प्रविवेश: entered.
Heroic (Vibheeshana) of exceptional splendour, whose brilliance spread widely like the radiance of the highly lustrous Sun entered his brother's abode.