Shiva Purana
नर्मदा सुरसाद्याश्च सप्तान्याश्च सहस्रशः॥ विंध्योद्भवा महानद्यस्सर्वपापहराश्शुभाः॥ १०॥
The great rivers issuing from Vindhya are seven, such as Narmadā, Surasā etc, and thousands of smaller ones are all auspicious. They quell all sins.
english translation
narmadA surasAdyAzca saptAnyAzca sahasrazaH॥ viMdhyodbhavA mahAnadyassarvapApaharAzzubhAH॥ 10॥
hk transliteration by Sanscript