Valmiki Ramayana Ayodhya Kanda Sarga 12 Shloka 47
Original Shlokaअहं हि विषमद्यैव पीत्वा बहु तवाग्रतः। पश्यतस्ते मरिष्यामि रामो यद्यभिषिच्यते।।2.12.47।।
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रामः Rama, अभिषिच्यते यदि if installed (as princeregent), अहम् I, अद्यैव today itself, तव your, अग्रतः presence, बहु excessive, विषम् poison, पीत्वा drinking, ते पश्यतः even as you are watching, मरिष्यामि हि will indeed die.
If Rama is coronated I will die while as you are watching right in your presence today itself by drinking excessive poison.