Valmiki Ramayana Yuddha Kanda Sarga 119 Shloka 6
Original Shlokaन तथास्मिमहाबाहो यथामामवगच्छसि । प्रत्ययंगच्छमेस्वेनचारित्रेणैवतेशपे ।।6.119.6।।
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महाबाहो mighty armed, माम् me, यथा similarly, अवगच्छसि not as you think of me, तथा so also, न अस्मिI am not, मे my, प्रत्ययम् proof, गच्छ period, स्वेन myself, चारित्रेण my past, ते to you, शपे vow
"O Mighty armed! I am not as you think of me, so also show me a proof of it in my past. I swear on my past."