Valmiki Ramayana Ayodhya Kanda Sarga 8 Shloka 39
Original Shlokaयदा हि रामः पृथिवीमवाप्स्यति ध्रुवं प्रणष्टो भरतो भविष्यति। अतो हि सञ्चिन्तय राज्यमात्मजे परस्य चैवाद्य विवासकारणम्।।2.8.39।।
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राम: Rama, यदा हि when, पृथिवीम् this earth, अवाप्स्यति obtains, भरत: Bharata, ध्रृवम् certainly, प्रणष्ट: ruined, भविष्यति will become, अत: for that reason, आत्मजे your son, राज्यम् kingdom, अद्यैव right now, परस्य enemy Rama's, विवासकारणम् means of banishment, सञ्चिन्तय think over.
When Rama obtains this earth, Bharata will be certainly ruined. Therefore, right now think of the kingdom for your son and the means of banishment for your enemy, Rama. इत्यार्षे श्रीमद्रामायणे वाल्मीकीय आदिकाव्ये अयोध्याकाण्डे अष्टमस्सर्गः।। Thus ends the eighth sarga of Ayodhyakanda of the holy Ramayana, the first epic composed by sage Valmiki.