Valmiki Ramayana Sundara Kanda Sarga 1 Shloka 15
Original Shlokaपीड्यमानस्तु बलिना महेन्द्रस्तेन पर्वतः। रीतीर्निर्वर्तयामास काञ्चनाञ्जनराजतीः।।5.1.15।।
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बलिना by the powerful, तेन by him, पीड्यमानः having pressed, महेन्द्रः पर्वतः mount Mahendra, काञ्चनाञ्चनराजतीः of gold and silver, रीतीः streams, निर्वर्तयामास started forming.
Pressed by the powerful Hanuman, mount Mahendra let out streams of the hue of gold and silver (containing the ores of these minerals)৷৷