Valmiki Ramayana Ayodhya Kanda Sarga 115 Shloka 17
Original Shlokaभ्रात्रा हि मयि संन्यासो निक्षिप्त स्सौहृदादयम्। तमिमं पालयिष्यामि राघवागमनं प्रति।।2.115.17।।
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भ्रात्रा by my brother Rama, अयम् this (kingdom), संन्यासः on trust, सौहृदात् out of affection, मयि in me, निक्षिप्तः has been deposited, तम् such, इमम् this trust, राघवागमनं प्रति till Rama returns, पालयिष्यामि I will rule.
This kingdom has been given me by my brother out of affection as a trust. I shall safeguard it until Rama's return.