Valmiki Ramayana Ayodhya Kanda Sarga 52 Shloka 49
Original Shlokaयदि मे याचमानस्य त्यागमेव करिष्यसि। सरथोऽग्निं प्रवेक्ष्यामि त्यक्तमात्र इह त्वया।।2.52.49।।
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याचमानस्य request, मे my, त्यागमेव forsaking, करिष्यसि यदि if you, त्वया by you, त्यक्तमात्रः immediately after being forsaken, इह here, सरथः with the chariot, अग्निम् into fire प्रवेक्ष्यामि I will enter.
If you forsake me in spite of my request I shall immediately enter fire along with my chariot.