SB 9.9.4
ko ’pi dharayita vegam
patantya me mahi-tale
anyatha bhu-talam bhittva
nrpa yasye rasatalam
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Mother Ganges replied: When I fall from the sky to the surface of the planet earth, the water will certainly be very forceful. Who will sustain that force? If I am not sustained, I shall pierce the surface of the earth and go down to Rasatala, the Patala area of the universe.