Valmiki Ramayana Sundara Kanda Sarga 2 Shloka 46
Original Shlokaतदहं स्वेन रूपेण रजन्यां ह्रस्वतां गतः। लङ्कामभिपतिष्यामि राघवस्यार्थसिद्धये।।5.2.46।।
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तत् therefore, अहम् I, स्वेन रूपेण in my own form, ह्रस्वताम् in a tiny form, गतः assuming, राघवस्य Rama's, अर्थसिद्धये to accomplish, रजन्याम् in the night, लङ्काम् Lanka, अभिपतिष्यामि I shall jump.
'Therefore I shall transform myself into a tiny form and jump about the city of Lanka during night time in order to accomplish Raghava's purpose.