Srimad-Bhagavatam: Canto 10 - Chapter 1 - Verse 19


यावद् वत्सपवत्सकाल्पकवपुर्यावत् कराङ्‌‌घ्र्यादिकंयावद् यष्टिविषाणवेणुदलशिग् यावद् विभूषाम्बरम् ।यावच्छीलगुणाभिधाकृतिवयो यावद् विहारादिकंसर्वं विष्णुमयं गिरोऽङ्गवदज: सर्वस्वरूपो बभौ ॥ १९ ॥


yāvad vatsapa-vatsakālpaka-vapur yāvat karāṅghry-ādikaṁyāvad yaṣṭi-viṣāṇa-veṇu-dala-śig yāvad vibhūṣāmbaramyāvac chīla-guṇābhidhākṛti-vayo yāvad vihārādikaṁsarvaṁ viṣṇumayaṁ giro ’ṅga-vad ajaḥ sarva-svarūpo babhau


By His Vāsudeva feature, Kṛṣṇa simultaneously expanded Himself into the exact number of missing cowherd boys and calves, with their exact bodily features, their particular types of hands, legs and other limbs, their sticks, bugles and flutes, their lunch bags, their particular types of dress and ornaments placed in various ways, their names, ages and forms, and their special activities and characteristics. By expanding Himself in this way, beautiful Kṛṣṇa proved the statement samagra-jagad viṣṇumayam: “Lord Viṣṇu is all-pervading.”


As stated in the Brahma-saṁhitā (5.33): Kṛṣṇa, paraṁ brahma, the Supreme Personality of Godhead, is ādyam, the beginning of everything; He is ādi-puruṣam, the ever-youthful original person. He can expand Himself in more forms than one can imagine, yet He does not fall down from His original form as Kṛṣṇa; therefore He is called Acyuta. This is the Supreme Personality of Godhead. Sarvaṁ viṣṇumayaṁ jagat. Sarvaṁ khalv idaṁ brahma. Kṛṣṇa thus proved that He is everything, that He can become everything, but that still He is personally different from everything (mat-sthāni sarva-bhūtāni na cāhaṁ teṣv avasthitaḥ). This is Kṛṣṇa, who is understood by acintya-bhedābheda-tattva philosophy. Pūrṇasya pūrṇam ādāya pūrṇam evāvaśiṣyate: Kṛṣṇa is always complete, and although He can create millions of universes, all of them full in all opulences, He remains as opulent as ever, without any change (advaitam). This is explained by different Vaiṣṇava ācāryas through philosophies such as viśuddhādvaita, viśiṣṭādvaita and dvaitādvaita. Therefore one must learn about Kṛṣṇa from the ācāryas. Ācāryavān puruṣo veda: one who follows the path of the ācāryas knows things as they are. Such a person can know Kṛṣṇa as He is, at least to some extent, and as soon as one understands Kṛṣṇa (janma karma ca me divyam evaṁ yo vetti tattvataḥ), one is liberated from material bondage (tyaktvā dehaṁ punar janma naiti mām eti so ’rjuna).