Valmiki Ramayana Yuddha Kanda Sarga 88 Shloka 33
Original Shlokaसःबभूवमहाभीमोनरराक्षससिंहयोः ।।6.88.33।। विमर्दस्तुमुलोयुद्धेपरस्परजयैषिणोः ।
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युद्धे in combat, परस्परजयैषिणोः to win in fight over each other, नरराक्षससिंहयोः Lakshmana and Indrajith, महाभीमः very frightening, सः he, विमर्द: pounding each other, तुमलः very, बभूव appeared
In that combat both Lakshmana and Indrajith pounding to win against each other was frightening.