Valmiki Ramayana Yuddha Kanda Sarga 26 Shloka 18
Original Shlokaवालिनस्सदृशःपुत्रस्सुग्रीवस्यसदाप्रियः । राघवार्थेपराक्रान्तश्शक्रार्थेवरुणोयथा ।।6.26.18।।
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वालिनः Vali's, सदृशः similar, पुत्रः son, सदा: ever, सुग्रीवस्य: Sugriva's, प्रियः beloved, शक्रार्थे: for the cause of Indra, वरुणोयथा: like Varuna, राघवार्थे: for the cause of Rama, पराक्रान्तः ready to show his valour.
"He is the son of Vali and is similar to him and is ever beloved of Sugriva. Jus t like Varuna fights for the cause of Indra, he is ready to show his valour for the cause of Rama."