Although they have no access to the Srimad-Bhagavatam, the followers of the Mayavada (impersonalist) school sometimes screw out an imaginary explanation of the original four verses, but we must accept the actual explanation given herein by Maitreya Muni
SB Canto 3
The Personality of Godhead, the master of all living entities, existed prior to the creation as one without a second. It is by His will only that creation is made possible and again everything merges in Him. This Supreme Self is symptomized by different names.
The great sage here begins to explain the purpose of the four original verses of the Śrīmad-Bhāgavatam. Although they have no access to the Śrīmad-Bhāgavatam, the followers of the Māyāvāda (impersonalist) school sometimes screw out an imaginary explanation of the original four verses, but we must accept the actual explanation given herein by Maitreya Muni because he, along with Uddhava, personally heard it directly from the Lord. The first line of the original four verses runs, aham evāsam evāgre. The word aham is misinterpreted by the Māyāvāda school into meanings which no one but the interpreter can understand. Here aham is explained as the Supreme Personality of Godhead, not the individual living entities. Before the creation, there was only the Personality of Godhead; there were no puruṣa incarnations and certainly no living entities, nor was there the material energy, by which the manifested creation is effected. The puruṣa incarnations and all the different energies of the Supreme Lord were merged in Him only.
The Personality of Godhead is described herein as the master of all other living entities. He is like the sun disc, and the living entities are like the molecules of the sun's rays. This existence of the Lord before the creation is confirmed by the śrutis: vāsudevo vā idaṁ agra āsīt na brahmā na ca śaṅkaraḥ, eko vai nārāyaṇa āsīn na brahmā neśānāḥ. Because everything that be is an emanation from the Personality of Godhead, He always exists alone without a second. He can so exist because He is all-perfect and omnipotent. Everything other than Him, including His plenary expansions, the viṣṇu-tattvas, is His part and parcel. Before the creation there were no Kāraṇārṇavaśāyī or Garbhodakaśāyī or Kṣīrodakaśāyī Viṣṇus, or was there Brahmā nor Śaṅkara. The Viṣṇu plenary expansion and the living entities beginning from Brahmā are separated parts and parcels. Although the spiritual existence was there with the Lord, the material existence was dormant in Him. By His will only is the material manifestation done and undone. The diversity of the Vaikuṇṭhaloka is one with the Lord, just as the diversity of soldiers is one with and the same as the king. As explained in Bhagavad-gītā (9.7), the material creation takes place at intervals by the will of the Lord, and in the periods between dissolution and creation, the living entities and the material energy remain dormant in Him.