Revākhaṇḍa of the Skandapurāṇa manuscripts (RKS) 95.15

95.15

tasya tīrthe bhavet puṇyaṃ tac chṛṇuṣva narādhipa /
yāvad asthimanuṣyasya tiṣṭhate narmadāmbhasi //

the merit that accrues to him at that sacred bathing site—hear that, O king:
as long as a man's bone remains in the waters of the Narmadā,