Valmiki Ramayana Yuddha Kanda Sarga 50 Shloka 31
Original Shlokaचन्द्रश्चनामद्रोणश्चक्षीरोदेसागरोत्तमे । अमृतंयत्रमथितंतत्रतेपरमौषधी ।।6.50.31।।
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यत्र there, अमृतम् nectar of immortality, मथितम् was churned, सागरोत्तमे foremost of oceans, क्षीरोदे milky ocean, चन्द्रश्च Chandra's, द्रोणश्च Drona's, ते they, परमौषधी supreme medicine, तत्र present.
"There, where the milky ocean, the foremost of oceans, was churned, two mountains have risen by the name Chandra and Drona. The supreme herbs of medicine are present there."