nānyad yat sad-asat param
paścād ahaṁ yad etac ca
yo 'vaśiṣyeta so 'smy aham
aham-I, the Personality of Godhead; eva-certainly; āsam-existed; eva-only; agre-before the creation; na-never; anyat-anything else; yat-which; sat-the effect; asat-the cause; param-the supreme; paścāt-at the end; aham-I, the Personality of Godhead; yat-which; etat-this creation; ca-also; yaḥ-who; avaśiṣyeta-remains; saḥ-that; asmi-am; aham-I, the Personality of Godhead.
"Prior to the cosmic creation, only I exist, and no phenomena exist, either gross, subtle or primordial. After creation, only I exist in everything, and after annihilation, only I remain eternally.
The words paścād aham indicate that the Lord exists after the dissolution of the cosmic manifestation. When the material world is dissolved, the Lord still exists personally in the Vaikuṇṭhas. During the creation the Lord also exists as He is in the Vaikuṇṭhas, and He also exists as the Supersoul within the material universes. This is confirmed in the Brahma-saṁhitā (5.37). Goloka eva nivasati: although He is perfectly and eternally present in Goloka Vṛndāvana in Vaikuṇṭha, He is nevertheless all-pervading (akhilātma-bhūtaḥ). The all-pervading feature of the Lord is called the Supersoul. In the Bhagavad-gītā it is said, ahaṁ kṛtsnasya jagataḥ prabhavaḥ: the cosmic manifestation is a display of the energy of the Supreme Lord. The material elements (earth, water, fire, air, ether, mind, intelligence and false ego) display the inferior energy of the Lord, and the living entities are His superior energy. Since the energy of the Lord is not different from Him, in fact everything that exists is Kṛṣṇa in His impersonal feature. Sunshine, sunlight and heat are not different from the sun, and yet simultaneously they are distinct energies of the sun. Similarly, the cosmic manifestation and the living entities are energies of the Lord, and they are considered to be simultaneously one with and different from Him. The Lord therefore says, "I am everything," because everything is His energy and is therefore nondifferent from Him.