Skandapurana 6.3.82.15

6.3.82.15

sa snātaḥ sarvatīrtheṣu somapānaṃ dine dine .
gaṅgādyāḥ saritaḥ sarvāḥ samudrāśca sarāṃsi ca .
kalpānte saṃkṣayaṃ yānti na mṛtā tena narmadā .. 82.15 ..

He has bathed in all the sacred fords and drinks soma day after day.
All rivers beginning with the Gaṅgā, the oceans, and the lakes
perish at the end of an aeon; therefore the Narmadā is immortal.