Valmiki Ramayana Yuddha Kanda Sarga 70 Shloka 21
Original Shlokaतश्चिक्षेपशैलाग्रंनीलस्त्रिशिरसेतदा । तद्रावणसुतोधीमाबनिभेदनिशितैश्शरैः ।।6.70.21।।
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ततः there upon, नीलः Neela, तदा then, त्रिशिरसे on Trisira, शैलाग्रम् peak of mountain, चिक्षेप broken to pieces, धीमान् wise, रावणसुतः Ravana's son, निशितैः sharp, शरैः arrows, तत् then, बिभेद broke to pieces.
Thereafter Neela hit Trisira with the peak of the mountain and Ravana's son broke the mountain into pieces with arrows.