Srimad Bhagavatam Canto 02, Chapter 01, Text 39

SB 2.1.39

sa sarva-dhi-vrtty-anubhuta-sarva
atma yatha svapna-janeksitaikah
tam satyam ananda-nidhim bhajeta
nanyatra sajjed yata atma-patah
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
One should concentrate his mind upon the Supreme Personality of Godhead, who alone distributes Himself in so many manifestations just as ordinary persons create thousands of manifestations in dreams. One must concentrate the mind on Him, the only all-blissful Absolute Truth. Otherwise one will be misled and will cause his own degradation.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
In this verse, the process of devotional service is indicated by the great gosvami Srila Sukadeva. He tries to impress upon us that instead of diverting our attention to several branches of self-realization, we should concentrate upon the Supreme Personality of Godhead as the supreme object of realization, worship and devotion. Self-realization is, as it were, offering a fight for eternal life against the material struggle for existence, and therefore by the illusory grace of the external energy, the yogi or the devotee is faced with many allurements which can entangle a great fighter again in the bondage of material existence. A yogi can attain miraculous successes in material achievements, such as anima and laghima, by which one can become more minute than the minutest or lighter than the lightest, or in the ordinary sense, one may achieve material benedictions in the shape of wealth and women. But one is warned against such allurements because entanglement again in such illusory pleasure means degradation of the self and further imprisonment in the material world. By this warning, one should follow one’s vigilant intelligence only.
The Supreme Lord is one, and His expansions are various. He is therefore the Supersoul of everything. When a man sees anything, he must know that his seeing is secondary and the Lord’s seeing is primary. One cannot see anything without the Lord’s having first seen it. That is the instruction of the Vedas and the Upanisads. So whatever we see or do, the Supersoul of all acts of seeing or doing is the Lord. This theory of simultaneous oneness and difference between the individual soul and the Supersoul is propounded by Lord Sri Caitanya Mahaprabhu as the philosophy of acintya-bhedabheda-tattva. The virat-rupa, or the gigantic feature of the Supreme Lord, includes everything materially manifested, and therefore the virat or gigantic feature of the Lord is the Supersoul of all living and nonliving entities. But the virat-rupa is also the manifestation of Narayana or Visnu, and going further on and on one will eventually see that Lord Krsna is the ultimate Supersoul of everything that be. The conclusion is that one should unhesitatingly become a worshiper of Lord Krsna, or, for that matter, His plenary expansion Narayana, and none else. In the Vedic hymns, it is clearly said that first of all Narayana cast a glance over matter and thus there was creation. Before creation, there was neither Brahma nor Siva, and what to speak of others. Sripada Sankaracarya has definitely accepted this, that Narayana is beyond the material creation and that all others are within the material creation. The whole material creation, therefore, is one with and different from Narayana, simultaneously, and this supports the acintya-bhedabheda-tattva philosophy of Lord Sri Caitanya Mahaprabhu. Being an emanation from the glancing potency of Narayana, the whole material creation is nondifferent from Him. But because it is the effect of His external energy (bahiranga maya) and is aloof from the internal potency (atma-maya), the whole material creation is different from Him at the same time. The example given in this verse very nicely is that of the dreaming man. The dreaming man creates many things in his dream, and thus he himself becomes the entangled seer of the dream and is also affected by the consequences. This material creation is also exactly a dreamlike creation of the Lord, but He, being the transcendental Supersoul, is neither entangled nor affected by the reactions of such a dreamlike creation. He is always in His transcendental position, but essentially He is everything, and nothing is apart from Him. As a part of Him, one should therefore concentrate on Him only, without deviation; otherwise one is sure to be overcome by the potencies of the material creation, one after another. It is confirmed in the Bhagavad-gita (9.7) as follows:
sarva-bhutani kaunteya
 prakrtim yanti mamikam
kalpa-ksaye punas tani
 kalpadau visrjamy aham
“O son of Kunti, at the end of the millennium every material manifestation enters into My nature, and at the beginning of another millennium, by My potency, I again create.”
The human life, however, is an opportunity to get out of this repetition of creation and annihilation. It is a means whereby one may escape the Lord’s external potency and enter into His internal potency.
Thus end the Bhaktivedanta purports of the Second Canto, First Chapter, of the Srimad-Bhagavatam, entitled “The First Step in God Realization.”
Srimad Bhagavatam Canto 02, Chapter 01, Text 38
Srimad Bhagavatam Canto 02, Chapter 01 Overview