Valmiki Ramayana Kishkindha Kanda Sarga 28 Shloka 48

महीधराणाम् of the mountains, धाराभिधौतानि washed by the rain water, महान्ति huge, कूटानि mountain peaks, लम्बमानैः by the hanging, मुक्ताकलापैरिव like the strings of pearls, महाप्रमाणैः by long , विपुलैः by many, प्रपातैः water falling down, अधिकम् excessively, विभान्ति appeared.

'The huge mountain peaks are washed by the heavy downpour of rain which look like long strings of pearls hanging.