Valmiki Ramayana Sundara Kanda Sarga 1 Shloka 154
Original Shlokaअन्यकार्यविषक्तस्य बद्धवैरस्य राक्षसैः। तस्य सीता हृता भार्या रावणेन यशस्विनी।।5.1.154।।
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राक्षसैः with rakshasas, बद्धवैरस्य deeprooted enmity, तस्य his, अन्यकार्यविषक्तस्य while he was engaged in some other work, यशस्विनी a glorious lady, भार्या wife, सीता Sita, रावणेन by Ravana, हृता was abducted.
"While Rama was engaged otherwise, his glorious wife Sita was abducted by Ravana actuated by deeprooted enmity of demons with him.