Valmiki Ramayana Ayodhya Kanda Sarga 52 Shloka 25
Original Shlokaएतदर्थं हि राज्यानि प्रशासति नरेश्वराः। यदेषां सर्वकृत्येषु मनो न प्रतिहन्यते।।2.52.25।।
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एषाम् whatever, मनः in the mind, सर्वकृत्येषु to do all those, यत् न प्रतिहन्यते creater no obstacles, एतदर्थम् that is why, नरेश्वराः king, राज्यानि kingdom, प्रशासति हि rule.
The minds of kings create no hurdles in all that they want to do. That is why they rule kingdoms.