Valmiki Ramayana Ayodhya Kanda Sarga 14 Shloka 47
Original Shlokaयथा नन्दति तेजस्वी सागरो भास्करोदये।।2.14.47।। प्रीतः प्रीतेन मनसा तथाऽनन्दघन स्स्वतः।
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स्वतः inherently, आनन्दघनः full of delight, तेजस्वी mighty, सागरः ocean, भास्करोदये at sunrise, यथा just as that, नन्दति rejoices, तथा in that way, प्रीतेन pleased, मनसा mind, प्रीतः became delighted.
Just as the mighty ocean rejoices at sunrise, the inherently cheerful Sumantra became delighted to see the king.