Valmiki Ramayana Sundara Kanda Sarga 21 Shloka 12
Original Shlokaतथेयं त्वां समासाद्य लङ्का रत्नौघसङ्कुला।।5.21.12।। अपराधात्तवैकस्य नचिराद्विनशिष्यति।
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तथा in that way, त्वाम् you, समासाद्य having got, रत्नौघसङ्कुला filled with gems, इयम् this, लङ्का Lanka, एकस्य a single person, तव your, अपराधात् for your crime, न चिरात् very soon, विनशिष्यति will be destroyed.
"Having got you as its ruler, this Lanka filled with gems (riches) will perish without delay for the crime of one individual.