Valmiki Ramayana Yuddha Kanda Sarga 114 Shloka 99
Original Shlokaशतक्रतुमुखैर्वीरैःश्रूयते न पराजितः ।।6.114.99।। महात्माबलसम्पन्नोरावणोलोकरावणः ।
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महात्मा great self, बलसम्पन्नः rich in prowess, लोकरावणः tyranny to the world, रावणः Ravana, शतक्रुमुखैः a hundred sacrifices, वीरैः hero, न पराजितः not defeated, श्रूयते heard
"Though he is richly endowed with prowess, he is a tyranny to the world, who has performed a hundred sacrifices (like Indra) and never got defeated, I heard."