Valmiki Ramayana Ayodhya Kanda Sarga 53 Shloka 12
Original Shlokaस हि सर्वस्य राज्यस्य मुखमेकं भविष्यति। ताते च वयसाऽतीते मयि चारण्यमास्थिते।।2.53.12।।
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ताते dear one, वयसा with age, अतीते advanced, मयि च I also, अरण्यम् the forest, आस्थिते dwelling, सः that Bharata, सर्वस्य entire, राज्यस्य kingdom, एकम् alone, मुखम् chief man, भविष्यति will remain.
The king is advanced in age and I have to dwell in the forest. Therefore, Bharata alone will be the chief of this entire kingdom.