Srimad-Bhagavatam: Canto 11 - Chapter 1 - Verse 16

Sanskrit:

त्वत्त: पुमान् समधिगम्य ययास्य वीर्यंधत्ते महान्तमिव गर्भममोघवीर्य: ।सोऽयं तयानुगत आत्मन आण्डकोशंहैमं ससर्ज बहिरावरणैरुपेतम् ॥ १६ ॥

ITRANS:

tvattaḥ pumān samadhigamya yayāsya vīryaṁdhatte mahāntam iva garbham amogha-vīryaḥso ’yaṁ tayānugata ātmana āṇḍa-kośaṁhaimaṁ sasarja bahir āvaraṇair upetam

Translation:

My dear Lord, the original puruṣa-avatāra, Mahā-Viṣṇu, acquires His creative potency from You. Thus with infallible energy He impregnates material nature, producing the mahat-tattva. Then the mahat-tattva, the amalgamated material energy, endowed with the potency of the Lord, produces from itself the primeval golden egg of the universe, which is covered by various layers of material elements.

Purport:

In the previous verses the supremacy of the Personality of Godhead has been established in relation to the living entity and material nature. In this verse it is clearly stated that Lord Kṛṣṇa is the source of the greatest Viṣṇu incarnation, Mahā-Viṣṇu, and that Mahā-Viṣṇu acquires His creative potency from Lord Kṛṣṇa. It would therefore be foolish to surmise that Lord Kṛṣṇa is an expansion of Viṣṇu. In this regard the opinion of the demigods, headed by Brahmā, can be taken as final.