SB 2.1.27
dve januni sutalam visva-murter
uru-dvayam vitalam catalam ca
mahitalam taj-jaghanam mahipate
nabhastalam nabhi-saro grnanti
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The knees of the universal form are the planetary system of the name Sutala, and the two thighs are the Vitala and Atala planetary systems. The hips are Mahitala, and outer space is the depression of His navel.