Valmiki Ramayana Sundara Kanda Sarga 3 Shloka 20
Original Shlokaथ सा हरिशार्दूलं प्रविशन्तं महाबलम्। नगरी स्वेन रूपेण ददर्श पवनात्मजम्।।5.3.20।।
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अथ then, सा नगरी that city, हरिशार्दूलम् tiger among vanaras, महाबलम् of great prowess, पवनात्मजम् son of the Windgod, प्रविशन्तम् while he entered, स्वेन in her real, रूपेण form, ददर्श saw.
Assuming her real form the presiding deity of Lanka noticed the son of the Windgod, the tiger among vanaras of great prowess entering the city.