Valmiki Ramayana Ayodhya Kanda Sarga 73 Shloka 20
Original Shlokaअस्मिन्कुले हि पूर्वेषां ज्येष्ठो राज्येऽभिषिच्यते। अपरे भ्रातरस्तस्मिन्प्रवर्तन्ते समाहिताः।।2.73.20।।
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अस्मिन् in this, कुले race, पूर्वेषाम् of our ancestors, ज्येष्ठः the eldest one, राज्ये in the kingdom, अभिषिच्यते हि is indeed installed, अपरे the rest of them, भ्रातरः brothers, तस्मिन् in the eldest, समाहिताः concentrate their attention, प्रवर्तन्ते conduct themselves.
In our race only the eldest son is installed in the kingdom and the other brothers behave with utmost respect towards him.