Valmiki Ramayana Yuddha Kanda Sarga 36 Shloka 16
Original Shlokaरावणस्तुसहामात्योमन्त्रयित्वाविमृश्यच । लङ्कायामतुलांगुप्तिंकारयामासराक्षसः ।।6.36.16।।
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राक्षसः Rakshasas, रावणस्तु with Ravana, सहामात्यः with companions, मन्त्रयित्वा with ministers, विमृश्य holding discussions, तदा then, लङ्कायां for Lanka, अतुलां unequalled, गुप्तिम् protection, कारयामास made arrangements.
Ravana then held discussions with his companions and ministers and made unequalled arrangements for (safety of) Lanka.