Narada said The name of this (region) is Rasatala which is the seventh region in the nether regions of the earth, where lives Surabhi, the mother of cows, who was born out of nectar.
नारद उवाच इदं रसातलं नाम सप्तमं पृथिवीतलम्। यत्रास्ते सुरभिर्माता गवाममृतसम्भवा॥