Valmiki Ramayana Sundara Kanda Sarga 1 Shloka 19
Original Shlokaशिरोभिः पृथुभिः सर्पा व्यक्तस्वस्तिकलक्षणैः। वमन्तः पावकं घोरं ददंशुर्दशनैः शिलाः।।5.1.19।।
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सर्पाः snakes, व्यक्तस्वस्तिकलक्षणैः with signs of swastika marks, पृथुभिः by wide ones, शिरोभिः with hoods, घोरम् terrible, पावकम् fire, वमन्तः poured out, दशनैः with fangs, शिलाः ददंशुः bit the rocks.
The snakes spread out their broad hoods manifesting swastika marks on them and bit the rocks with their fangs pouring out terrible fire.