Srimad-Bhagavatam: Canto 2 - Chapter 1 - Verse 28


आसिसृप्सो: पुर: पुर्या नाभिद्वारमपानत: ।तत्रापानस्ततो मृत्यु: पृथक्त्वमुभयाश्रयम् ॥ २८ ॥


āsisṛpsoḥ puraḥ puryānābhi-dvāram apānataḥtatrāpānas tato mṛtyuḥpṛthaktvam ubhayāśrayam


Thereafter, when He desired to move from one body to another, the navel and the air of departure and death were combinedly created. The navel is the shelter for both, namely death and the separating force.


The prāṇa-vāyu continues the life, and the apāna-vāyu stops the living force. Both the vibrations are generated from the abdominal hole, the navel. This navel is the joint from one body to the other. Lord Brahmā was born of the abdominal hole of Garbhodakaśāyī Viṣṇu as a separate body, and the same principle is followed even in the birth of any ordinary body. The body of the child develops from the body of the mother, and when the child is separated from the body of the mother, it is separated by cutting the navel joint. And that is the way the Supreme Lord manifested Himself as separated many. The living entities are therefore separated parts, and thus they have no independence.