Valmiki Ramayana Sundara Kanda Sarga 1 Shloka 123
Original Shlokaपूर्वं कृतयुगे तात पर्वताः पक्षिणोऽभवन्। ते हि जग्मुर्दिशः सर्वा गरुडानिलवेगिनः।।5.1.123।।
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तात O dear son, पूर्वम् formerly, कृतयुगे in Krita yuga, पर्वताः mountains,पक्षिणः had wings, अभवन् endowed, ते they, गरुडानिलवेगिनः swift like Garuda and wind, सर्वाः all, दिशः directions, जग्मुः went about.
"Formerly in Kritayuga, O dear, mountains were endowed with wings. They used to move speedily in all directions like Garuda and the Windgod.