Srimad-Bhagavatam: Canto 10 - Chapter 1 - Verse 16

Sanskrit:

अत्रैव मायाधमनावतारेह्यस्य प्रपञ्चस्य बहि: स्फुटस्य ।कृत्‍स्‍नस्य चान्तर्जठरे जनन्यामायात्वमेव प्रकटीकृतं ते ॥ १६ ॥

ITRANS:

atraiva māyā-dhamanāvatārehy asya prapañcasya bahiḥ sphuṭasyakṛtsnasya cāntar jaṭhare jananyāmāyātvam eva prakaṭī-kṛtaṁ te

Translation:

My dear Lord, in this incarnation You have proved that You are the supreme controller of Māyā. Although You are now within this universe, the whole universal creation is within Your transcendental body — a fact You demonstrated by exhibiting the universe within Your abdomen before Your mother, Yaśodā.

Purport:

Lord Brahmā here describes the inconceivable spiritual potency of the Lord. We may find a pot within a house, but we can hardly expect to find the house within the same pot. By the Lord’s spiritual potency, however, He can appear within this universe and simultaneously exhibit all the universes within His body. One may argue that since the universes seen by mother Yaśodā within Lord Kṛṣṇa’s abdomen were within the Lord’s body, they are different from the illusory material universes manifest externally. Here Lord Brahmā refutes that argument, however. Lord Kṛṣṇa is māyā-dhamana, the supreme controller of illusion. By the Lord’s own supreme mystic potency, He can bewilder even illusion herself, and thus the Lord actually exhibited all the material universes within His body. This is māyātvam, the supreme bewildering potency of the Personality of Godhead.