Valmiki Ramayana 1.36.3
त्रीन् पथो हेतुना केन पावयेत् लोक पावनी ।कथम् गङ्गा त्रिपथगा विश्रुता सरित् उत्तमा॥
trīn patho hetunā kena pāvayet loka pāvanī |katham gaṅgā tripathagā viśrutā sarit uttamā ||
Our plain-language meaning of this verse is waiting for scholar review.
Open in the book