Valmiki Ramayana Bala Kanda Sarga 67 Shloka 18
Original Shlokaतस्य शब्दो महानासीत् निर्घातसमनिस्वन:। भूमिकम्पश्च सुमहान् पर्वतस्येव दीर्यत:।।1.67.18।।
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तस्य its, शब्द: sound, निर्घातसमनिस्वन: equalled to the clap of a thunder, महान् great, आसीत् became, पर्वतस्य of a mountain, दीर्यत: as if splitting, सुमहान् great, भूमिकम्पश्च trembling of the earth.
It generated a loud sound like the clap of thunder, like the trembling of the earth and the splitting of a mountain.