Srimad-Bhagavatam: Canto 2 - Chapter 1 - Verse 27
Sanskrit:
द्वे जानुनी सुतलं विश्वमूर्ते-रूरुद्वयं वितलं चातलं च ।महीतलं तज्जघनं महीपतेनभस्तलं नाभिसरो गृणन्ति ॥ २७ ॥
ITRANS:
dve jānunī sutalaṁ viśva-mūrterūru-dvayaṁ vitalaṁ cātalaṁ camahītalaṁ taj-jaghanaṁ mahīpatenabhastalaṁ nābhi-saro gṛṇanti
Translation:
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 Mahītala, and outer space is the depression of His navel.