Valmiki Ramayana Ayodhya Kanda Sarga 66 Shloka 12
Original Shlokaसाऽहमद्यैव दिष्टान्तं गमिष्यामि पतिव्रता। इदं शरीर मालिङ्ग्य प्रवेक्ष्यामि हुताशनम्।।2.66.12।।
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पतिव्रता of faithful wife, सा अहम् such as myself, अद्यैव now itself, दिष्टान्तम् death, गमिष्यामि will go to, इदम् this, शरीरम् body, आलिङ्ग्य clasping, हुताशनम् in the fire, प्रवेक्ष्यामि I shall enter.
As his faithful wife, I shall enter the fire by clasping this (Dasaratha's) body and go to death today itself