Srimad Bhagavatam Canto 09, Chapter 07, Text 03

SB 9.7.3

gandharvan avadhit tatra
 vadhyan vai visnu-sakti-dhrk
nagal labdha-varah sarpad
 abhayam smaratam idam
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
There in Rasatala, the lower region of the universe, Purukutsa, being empowered by Lord Visnu, was able to kill all the Gandharvas who deserved to be killed. Purukutsa received the benediction from the serpents that anyone who remembers this history of his being brought by Narmada to the lower region of the universe will be assured of safety from the attack of snakes.
Srimad Bhagavatam Canto 09, Chapter 07, Text 02
Srimad Bhagavatam Canto 09, Chapter 07, Text 04