SB 5.24.30
tato ’dhastad rasatale daiteya danavah panayo nama nivata-kavacah kaleya hiranya-puravasina iti
vibudha-pratyanika utpattya mahaujaso maha-sahasino bhagavatah sakala-lokanubhavasya harer eva tejasa
pratihata-balavalepa bilesaya iva vasanti ye vai saramayendra-dutya vagbhir mantra-varnabhir indrad
bibhyati.
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Beneath Mahatala is the planetary system known as Rasatala, which is the abode of the demoniac sons of Diti and Danu. They are called Panis, Nivata-kavacas, Kaleyas and Hiranya-puravasis [those living in Hiranya-pura]. They are all enemies of the demigods, and they reside in holes like snakes. From birth they are extremely powerful and cruel, and although they are proud of their strength, they are always defeated by the Sudarsana cakra of the Supreme Personality of Godhead, who rules all the planetary systems. When a female messenger from Indra named Sarama chants a particular curse, the serpentine demons of Mahatala become very afraid of Indra.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
It is said that there was a great fight between these serpentine demons and Indra, the King of heaven. When the defeated demons met the female messenger Sarama, who was chanting a mantra, they became afraid, and therefore they are living in the planet called Rasatala.