narmada bhratrbhir datta
taya rasatalam nito
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The serpent brothers of Narmada gave Narmada to Purukutsa. Being sent by Vasuki, she took Purukutsa to the lower region of the universe.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Before describing the descendants of Purukutsa, the son of Mandhata, Sukadeva Gosvami first describes how Purukutsa was married to Narmada, who was induced to take him to the lower region of the universe.