Valmiki Ramayana Yuddha Kanda Sarga 101 Shloka 17
Original Shlokaनीलमेघनिभांश्चास्यसदश्वान् पर्वतोपमान् । जघानाप्लुत्यगदयारावणस्यविभीषणः ।।6.101.17।।
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विभीषणः Vibheeshana, आप्लुत्य formidable, गदया with mace, अस्य his, रावणस्य Ravana's, नीलमेघनिभान् like dark cloud, पर्वतोपमान् like mountain, सदश्वान् his horses, जघाम struck
Vibheeshana struck with his formidable mace the horses of Ravana which were like dark clouds and huge like mountains.