SB 1.3 - The form of Mahā-Viṣṇu
At the end of previous chapter it was said that the Lord was absorbed in various līlāvatāras. In this chapter, Sūta Gosvāmī will first describe the Lord’s forms as puruṣa avatāras for creating the universe. Then he will describe the Lord’s many entries into the universe as the līlā avatāras. These descriptions will inspire Sūta to proclaim Kṛṣṇa the Supreme Personality of Godhead.
In the beginning of creation, the Lord expanded Himself in the universal form of the puruṣa incarnation and manifested all the ingredients for the material creation. It is said that the Lord accepted this form (jagṛhe pauruṣam rūpam) but this does not mean it is a temporary one. Therefore it is described as sambhūtam, samyag bhūtam: existing continuously. It is always situated in its svarūpa which is the highest truth. The Lord accepted this form of the puruṣa who eternally exists for creating the universes. He accepts a form which already exists. It is just like saying ‘He accepted a pot’, and this implies the pot already exists.
For the purpose of creating the material universe, thus there was the creation of the 16 principles of material action. The original Personality of Godhead Vāsudeva is full with all opulences. Part of His opulence is manifested as impersonal Brahman, and part of His opulence is manifested as Paramātmā. The Lord of Vaikuṇṭha accepted the form of the puruṣa who is like the full moon with 16 digits, being full of forms like Matsya and Kūrma. The puruṣa feature described here is the original Paramātmā manifestation of the Lord. There are three puruṣa features in the material creation, and this form is known as the Kāraṇodakaśāyī Viṣṇu or Mahā-Viṣṇu, who glances over prakṛti, and the other two are known as the Garbhodakaśāyī Viṣṇu and the Kṣīrodakaśāyī Viṣṇu. The innumerable universes are generated from the skin holes of this Kāraṇodakaśāyī Viṣṇu and in each of the universes the Lord enters as Garbhodakaśāyī Viṣṇu.