SB 03.08.15 tal loka-padmam sa u eva visnuh... cited

Expressions researched:
"pravivisat sarva-gunavabhasam" |"svayambhuvam yam sma vadanti so 'bhut" |"tal loka-padmam sa u eva visnuh" |"tasmin svayam vedamayo vidhata"

SB Canto 3

SB 3.8.15, Translation and Purport:

Into that universal lotus flower Lord Viṣṇu personally entered as the Supersoul, and when it was thus impregnated with all the modes of material nature, the personality of Vedic wisdom, whom we call the self-born, was generated.

This lotus flower is the universal virāṭ form, or the gigantic form of the Lord in the material world. It becomes amalgamated in the Personality of Godhead Viṣṇu, in His abdomen, at the time of dissolution, and it becomes manifest at the time of creation. This is due to Garbhodakaśāyī Viṣṇu, who enters into each of the universes. In this form is the sum total of all the fruitive activities of the living entities conditioned by material nature, and the first of them, namely Brahmā, or the controller of the universe, is generated from this lotus flower. This first-born living being, unlike all the others, has no material father, and thus he is called self-born, or svayambhū. He goes to sleep with Nārāyaṇa at the time of devastation, and when there is another creation, he is born in this way. From this description we have the conception of three—the gross virāṭ form, the subtle Hiraṇyagarbha and the material creative force, Brahmā.

CC Adi-lila

CC Adi 5.93, Translation and Purport:

I offer my full obeisances unto the feet of Śrī Nityānanda Rāma, a partial part of whom is Garbhodakaśāyī Viṣṇu. From the navel of Garbhodakaśāyī Viṣṇu sprouts the lotus that is the birthplace of Brahmā, the engineer of the universe. The stem of that lotus is the resting place of the multitude of planets.

In the Mahābhārata, Śānti-parva, it is said that He who is Pradyumna is also Aniruddha. He is also the father of Brahmā. Thus Garbhodakaśāyī Viṣṇu and Kṣīrodakaśāyī Viṣṇu are identical plenary expansions of Pradyumna, the original Deity of Brahmā, who is born from the lotus flower. It is Pradyumna who gives Brahmā direction for cosmic management. A full description of Brahmā’s birth is given in Śrīmad-Bhāgavatam (SB 3.8.15)-(SB 3.8.16).

Describing the features of the three puruṣas, the Laghu-bhāgavatāmṛta says that Garbhodakaśāyī Viṣṇu has a four-handed form, and when He Himself enters the hollow of the universe and lies down in the ocean of milk He is known as Kṣīrodakaśāyī Viṣṇu, who is the Supersoul of all living entities, including the demigods. In the Sātvata-tantra it is said that the third puruṣa incarnation, Kṣīrodakaśāyī Viṣṇu, is situated as the Supersoul in everyone's heart. This Kṣīrodakaśāyī Viṣṇu is an expansion of Garbhodakaśāyī Viṣṇu for pastimes.