Valmiki Ramayana Sundara Kanda Sarga 1 Shloka 64
Original Shlokaतस्य वानरसिंहस्य प्लवमानस्य सागरम्।।5.1.64।। कक्षान्तरगतो वायुर्जीमूत इव गर्जति।
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सागरम् ocean, प्लवमानस्य while he was crossing, तस्य his, वानरसिंहस्य lion like vanara, कक्षान्तरगतः through the armpits, वायुः wind, जीमूतः इव like thundering cloud, गर्जति roared.
The wind passing through the arm pits of the lionlike vanara crossing the ocean sounded like a thundering cloud.