Valmiki Ramayana Kishkindha Kanda Sarga 30 Shloka 42

व्यपेतपङ्कासु in spots cleared of mud, सवालुकासु sand dunes, प्रसन्नतोयासु pure water, सगोकुलासु with cows, ससारसारावनिनादितासु where sarasa birds are singing delightfully, नदीषु in the rivers, हंसाः swans, हृष्टाः happily, निपतन्ति reach.

'The swans are full of joy, flocking on the sand banks of rivers crowded with cows where the water is pure and devoid of mud. The rivers are full of sarasa birds and swans who are singing delightfully.