Srimad Bhagavatam Canto 04, Chapter 24, Text 63

 SB 4.24.63

tvam eka adyah purusah supta-saktis
 taya rajah-sattva-tamo vibhidyate
mahan aham kham marud agni-var-dharah
 surarsayo bhuta-gana idam yatah
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
My dear Lord, You are the only Supreme Person, the cause of all causes. Before the creation of this material world, Your material energy remains in a dormant condition. When Your material energy is agitated, the three qualities — namely goodness, passion and ignorance — act, and as a result the total material energy — egotism, ether, air, fire, water, earth and all the various demigods and saintly persons — becomes manifest. Thus the material world is created.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
If the whole creation is one — that is, nothing but the Supreme Lord, or Visnu — then why do the expert transcendentalists make such categories as are found in the above verse? Why do learned and expert scholars distinguish between matter and spirit? In answer to these questions, Lord Siva says that spirit and matter are not creations of various philosophers, but are manifested by Lord Visnu, as described in this verse: tvam eka adyah purusah. Spiritual and material categories are made possible by the Supreme Personality of Godhead, but actually there are no such distinctions for the living entities who are eternally engaged in the service of the Lord. There is only a material world for those who want to imitate the Lord and become enjoyers. Indeed, the material world is nothing but forgetfulness of the original Supreme Personality of Godhead, the creator of everything. The distinction between matter and spirit is created by the sleeping energy of the Lord when the Lord wants to give some facility to those living entities who want to imitate the Lord in His enjoyment. It is only for them that this material world is created by the dormant energy of the Lord. For instance, sometimes children want to imitate their mother and cook in the kitchen, and at such a time the mother supplies them with some toys so that the children can imitate her cooking. Similarly, when some of the living entities want to imitate the activities of the Lord, this material cosmic manifestation is created for them by the Lord. The material creation is therefore caused by the Lord through His material energy. It is by the glance of the Lord that the material energy is activated. At that time the three material qualities are set into motion, and the material energy is manifested first in the form of the mahat-tattva, then egotism, then ether, then air, fire, water and earth. After the creation, the living entities are impregnated in the cosmic manifestation, and they emerge as Lord Brahma and the seven great rsis, then as different demigods. From the demigods come human beings, animals, trees, birds, beasts and everything else. The original cause, however, is the Supreme Personality of Godhead, as verified herein: tvam eka adyah purusah. This is also confirmed in Brahma-samhita (5.1):
isvarah paramah krsnah
anadir adir govindah
Those who are covered by the material energy cannot understand that the origin of everything is the Supreme Personality of Godhead, Krsna. This is summarized in the Vedanta aphorism janmady asya yatah (Vedanta-sutra 1.1.2). Krsna also confirms this in Bhagavad-gita (10.8):
aham sarvasya prabhavo
 mattah sarvam pravartate
iti matva bhajante mam
 budha bhava-samanvitah
“I am the source of all spiritual and material worlds. Everything emanates from Me. The wise who perfectly know this engage in My devotional service and worship Me with all their hearts.”
When Krsna says that He is the origin of everything (aham sarvasya prabhavah), He means that He is even the source of Lord Brahma, Lord Siva, the purusa-avataras, the material manifestation and all the living entities within the material world. Actually the word prabhava, “creation,” refers only to this material world, for since the spiritual world is eternally existing, there is no question of creation. In the catuh-sloki of Srimad-Bhagavatam, the Lord says, aham evasam evagre: “I was existing in the beginning before the creation.” (Bhag. 2.9.33) In the Vedas it is also said, eko narayana asit: “Before the creation there was only Narayana.” This is also confirmed by Sankaracarya. Narayanah paro ’vyaktat: “Narayana is transcendental to the creation.” (Gita-bhasya) Since all the activities of Narayana are spiritual, when Narayana said, “Let there be creation,” that creation was all-spiritual. The “material” only exists for those who have forgotten that Narayana is the original cause.
Srimad Bhagavatam Canto 04, Chapter 24, Text 62
Srimad Bhagavatam Canto 04, Chapter 24, Text 64