Srimad Bhagavatam Canto 02, Chapter 01, Text 26

SB 2.1.26

patalam etasya hi pada-mulam
pathanti parsni-prapade rasatalam
mahatalam visva-srjo ’tha gulphau
talatalam vai purusasya janghe
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
Persons who have realized it have studied that the planets known as Patala constitute the bottoms of the feet of the universal Lord, and the heels and the toes are the Rasatala planets. The ankles are the Mahatala planets, and His shanks constitute the Talatala planets.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
Outside the bodily existence of the Supreme Personality of Godhead, the manifested cosmic existence has no reality. Everything and anything of the manifested world rests on Him, as confirmed in the Bhagavad-gita (9.4), but that does not imply that everything and anything in the vision of a materialist is the Supreme Personality. The conception of the universal form of the Lord gives a chance to the materialist to think of the Supreme Lord, but the materialist must know for certain that his visualization of the world in a spirit of lording over it is not God realization. The materialistic view of exploitation of the material resources is occasioned by the illusion of the external energy of the Lord, and as such if anyone wants to realize the Supreme Truth by conceiving of the universal form of the Lord, he must cultivate the service attitude. Unless the service attitude is revived, the conception of virat realization will have very little effect on the seer. The transcendental Lord, in any conception of His form, is never a part of the material creation. He keeps His identity as Supreme Spirit in all circumstances and is never affected by the three material qualities, for everything material is contaminated. The Lord always exists by His internal energy.
The universe is divided into fourteen planetary systems. Seven planetary systems, called Bhur, Bhuvar, Svar, Mahar, Janas, Tapas and Satya, are upward planetary systems, one above the other. There are also seven planetary systems downward, known as Atala, Vitala, Sutala, Talatala, Mahatala, Rasatala and Patala, gradually, one below the other. In this verse, the description begins from the bottom because it is in the line of devotion that the Lord’s bodily description should begin from His feet. Sukadeva Gosvami is a recognized devotee of the Lord, and he is exactly correct in the description.
Srimad Bhagavatam Canto 02, Chapter 01, Text 25
Srimad Bhagavatam Canto 02, Chapter 01, Text 27