Valmiki Ramayana Bala Kanda Sarga 67 Shloka 21
Original Shlokaभगवन् दृष्टवीर्यो मे रामो दशरथात्मज:। अत्यद्भुतमचिन्त्यं च न तर्कितमिदं मया।।1.67.21।।
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भगवन् O Worshipful one, दशरथात्मज: son of Dasatha, राम: Rama, मे to me, दृष्टवीर्य: having prowess, अत्यद्भुतम् marvellous, अचिन्त्यं च unimaginable, इदं this, मया by me, न तर्कितम् not conjectured.
"O Worshipful one I have witnessed the prowess of Rama, son of Dasaratha. I had not imagined that this marvellous feat could be ever accomplished.