SB 2.4.12

śrī-śuka uvāca
namaḥ parasmai puruṣāya bhūyase
 sad-udbhava-sthāna-nirodha-līlayā
gṛhīta-śakti-tritayāya dehinām
 antarbhavāyānupalakṣya-vartmane
Synonyms: 
śrī-śukaḥ uvāca — Śrī Śukadeva Gosvāmī said; namaḥ — offering obeisances; parasmai — the Supreme; puruṣāya — Personality of Godhead; bhūyase — unto the complete whole; sad-udbhava — the creation of the material world; sthāna — its maintenance; nirodha — and its winding up; līlayā — by the pastime of; gṛhīta — having accepted; śakti — power; tritayāya — three modes; dehinām — of all who possess material bodies; antaḥ-bhavāya — unto He who resides within; anupalakṣya — inconceivable; vartmane — one who has such ways.
Translation: 
Śukadeva Gosvāmī said: Let me offer my respectful obeisances unto the Supreme Personality of Godhead, who, for the creation of the material world, accepts the three modes of nature. He is the complete whole residing within the body of everyone, and His ways are inconceivable.
Purport: 

This material world is a manifestation of the three modes goodness, passion and ignorance, and the Supreme Lord, for the creation, maintenance and destruction of the material world, accepts three predominating forms as Brahmā, Viṣṇu and Śaṅkara (Śiva). As Viṣṇu He enters into every body materially created. As Garbhodakaśāyī Viṣṇu He enters into every universe, and as Kṣīrodakaśāyī Viṣṇu He enters the body of every living being. Lord Śrī Kṛṣṇa, being the origin of all viṣṇu-tattvas, is addressed here as paraḥ pumān, or Puruṣottama, as described in the Bhagavad-gītā (15.18). He is the complete whole. The puruṣāvatāras are therefore His plenary expansions. Bhakti-yoga is the only process by which one can become competent to know Him. Because the empiric philosophers and mystic yogīs cannot conceive of the Personality of Godhead, He is called anupalakṣya-vartmane, the Lord of the inconceivable way, or bhakti-yoga.