Valmiki Ramayana 7.98.14

सीता हि विमला साध्वी तव पूर्वपरायणा ।नागलोकं सुखं प्रायात्त्वदाश्रयतपोबलात्॥

sītā hi vimalā sādhvī tava pūrvaparāyaṇā |nāgalokaṃ sukhaṃ prāyāttvadāśrayatapobalāt ||

Our plain-language meaning of this verse is waiting for scholar review.