Valmiki Ramayana Ayodhya Kanda Sarga 3 Shloka 37
Original Shlokaतं पश्यमानो नृपतिस्तुतोष प्रियमात्मजम्।।2.3.37।। अलङ्कृतमिवात्मानमादर्शतलसंस्थितम्।
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तम् that, प्रियम् beloved, आत्मजम् son, पश्यमानः beholding, नृपतिः king, अलङ्कृतम् adorned, आदर्शतलसंस्थितम् image reflected in mirror, आत्मानमिव seeing himself, तुतोष experienced delight.
The king was delighted to see his beloved son as though he saw his own reflection adorning a mirror.