Valmiki Ramayana Yuddha Kanda Sarga 83 Shloka 18
Original Shlokaतस्य च व्यसनाभावाद्व्यसनंचागतेत्वयि । धर्मोभवत्यधर्मश्चपरस्परविरोधिनौ ।।6.83.18।।
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तस्य his, व्यसनाभावात् sorrowful feeling, त्वयि you, व्यसनम् agony, आगते experienced, धर्मेण by righteousness, अधर्मम् unrighteousness, अधर्मेण by unrighteousness, धर्मताम् righteousness, उपलभे will be acquired
" As Ravana has no sorrow and you have experienced agony the contraries of each other have changed the roles of righteousness and unrighteousness."