Valmiki Ramayana Ayodhya Kanda Sarga 74 Shloka 13
Original Shlokaकिं नावबुध्यसे क्रूरे नियतं बन्धुसंश्रयम्। ज्येष्ठं पितृसमं रामं कौसल्यायाऽत्मसम्भवम्।।2.74.13।।
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क्रूरे O cruel one, कौशल्यायाः Kausalya's, आत्मसम्भवम् born of her very self, रामम् Rama, नियतम् selfrestrained, बन्धुसंश्रयम् refuge for relations, ज्येष्ठम् eldest, पितृसमम् the equal of his father, किं नावबुध्यसे why do you not realise?
O cruel one why do you not realise that Rama, born of Kausalya, is the eldest son and equal to my father? He is selfrestrained and a refuge to his kith and kin.