Valmiki Ramayana Aranya Kanda Sarga 54 Shloka 13
Original Shlokaतत्र तामसितापाङ्गां शोकमोहपरायणाम्।।3.54.13।। निदधे रावणस्सीतां मयो मायामिवस्त्रियम्।
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रावणः Ravana, असितापाङ्गाम् a lady of dark eyelashes, शोकमोहपरायणाम् lady lost in sorrow, तां सीताम् that Sita, मयः demon Maya, मायामिव like Maya, तत्र there ( in the harem), नदधे kept.
Sita, with her dark eye lashes and lost in utter sorrow was kept in the harem by Ravana, like demon Maya kept Mayamayi.