It is a lovely romantic hymn sung by Rishi Vishwamitra. He prays to Vipāś (Beas) River and Sutudri (Sutlej) River to reduce water-level to below the height of cart-axles enabling the Bhaaratas to cross the rivers. In return, the rivers ask him, the poet, not to forget them so that posterity will remember them for allowing the passage.
That's interesting, do you make difference between vedic period and hinduism?
After all, as far as I understand, Rishi Vishwamitra is postvedic person, he lives after that period, so, he could not be the author of the hymn
what's the catch?