Valmiki Ramayana Yuddha Kanda Sarga 129 Shloka 41
Original Shlokaतेषांनोविप्रनष्टानांविन्ध्येपर्वतसत्तमो । भृशंशोकानितप्तानांमहान्कालो त्यवर्तत ।।6.129.41।।
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पर्वतसत्तमे foremost of mountains, विन्ध्ये Vindhya, विप्रनष्टानाम् lost way, भृशम् intense, शोकाभितप्तानाम् immersed in grief, तेषांनः their, महान् lot of, कालः time, अत्यवर्तत returned
"Monkeys that went to the foremost of mountains Vindhya lost their way and a lot of time and returned with intense grief."