SB 6.16.51
aham vai sarva-bhutani
bhutatma bhuta-bhavanah
sabda-brahma param brahma
mamobhe sasvati tanu
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
All living entities, moving and nonmoving, are My expansions and are separate from Me. I am the Supersoul of all living beings, who exist because I manifest them. I am the form of the transcendental vibrations like omkara and Hare Krsna Hare Rama, and I am the Supreme Absolute Truth. These two forms of Mine — namely, the transcendental sound and the eternally blissful spiritual form of the Deity, are My eternal forms; they are not material.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The science of devotional service has been instructed by Narada and Angira to Citraketu. Now, because of Citraketu’s devotional service, he has seen the Supreme Personality of Godhead. By performing devotional service, one advances step by step, and when one is on the platform of love of Godhead (prema pumartho mahan) he sees the Supreme Lord at every moment. As stated in Bhagavad-gita, when one engages in devotional service twenty-four hours a day (tesam satata-yuktanam bhajatam priti-purvakam) in accordance with the instructions of the spiritual master, his devotional service becomes more and more pleasing. Then the Supreme Personality of Godhead, who is within the core of everyone’s heart, speaks to the devotee (dadami buddhi-yogam tam yena mam upayanti te). Citraketu Maharaja was first instructed by his gurus, Angira and Narada, and now, having followed their instructions, he has come to the stage of seeing the Supreme Lord face to face. Therefore the Lord is now instructing him in the essence of knowledge.
The essence of knowledge is that there are two kinds of vastu, or substances. One is real, and the other, being illusory or temporary, is sometimes called nonfactual. One must consider these two kinds of existence. The real tattva, or truth, consists of Brahman, Paramatma, and Bhagavan. As stated in Srimad-Bhagavatam (1.2.11):
vadanti tat tattva-vidas
tattvam yaj jñanam advayam
brahmeti paramatmeti
bhagavan iti sabdyate
“Learned transcendentalists who know the Absolute Truth call this nondual substance Brahman, Paramatma or Bhagavan.” The Absolute Truth exists eternally in three features. Therefore, Brahman, Paramatma and Bhagavan combined are the substance.
The categories of emanations from the nonsubstance are two — activities and forbidden activities (karma and vikarma). Karma refers to the pious life or material activities performed during the day and the mental activities of dreams at night. These are more or less desired activities. Vikarma, however, refers to illusory activities, which are something like the will-o’-the-wisp. These are activities that have no meaning. For example, modern scientists imagine that life can be produced from chemical combinations, and they are very busy trying to prove this in laboratories throughout the world, although no one in history has been able to produce the substance of life from material combinations. Such activities are called vikarma.
All material activities are actually illusory, and progress in illusion is simply a waste of time. These illusory activities are called akarya, and one must learn of them from the instructions of the Supreme Personality of Godhead. As stated in Bhagavad-gita (4.17):
karmano hy api boddhavyam
boddhavyam ca vikarmanah
akarmanas ca boddhavyam
gahana karmano gatih
“The intricacies of action are very hard to understand. Therefore one should know properly what action is, what forbidden action is, and what inaction is.” One must learn of these directly from the Supreme Personality of Godhead, who, as Anantadeva, is instructing King Citraketu because of the advanced stage of devotional service he achieved by following the instructions of Narada and Angira.
Herein it is said, aham vai sarva-bhutani: the Lord is everything (sarva-bhutani), including the living entities and the material or physical elements. As the Lord says in Bhagavad-gita (7.4-5):
bhumir apo ’nalo vayuh
kham mano buddhir eva ca
ahankara itiyam me
bhinna prakrtir astadha
apareyam itas tv anyam
prakrtim viddhi me param
jiva-bhutam maha-baho
yayedam dharyate jagat
“Earth, water, fire, air, ether, mind, intelligence and false ego — all together these eight comprise My separated material energies. Besides this inferior nature, O mighty-armed Arjuna, there is a superior energy of Mine, which consists of the living entities, who are struggling with material nature and are sustaining the universe.” The living entity tries to lord it over the material or physical elements, but both the physical elements and the spiritual spark are energies emanating from the Supreme Personality of Godhead. Therefore the Lord says, aham vai sarva-bhutani: “I am everything.” Just as heat and light emanate from fire, these two energies — the physical elements and the living entities — emanate from the Supreme Lord. Therefore the Lord says, aham vai sarva-bhutani: “I expand the physical and spiritual categories.”
Again, the Lord, as the Supersoul, guides the living entities who are conditioned by the physical atmosphere. Therefore he is called bhutatma bhuta-bhavanah. He gives the living entity the intelligence with which to improve his position so that he may return home, back to Godhead, or if he does not want to go back to Godhead, the Lord gives him the intelligence with which to improve his material position. This is confirmed by the Lord Himself in Bhagavad-gita (15.15). Sarvasya caham hrdi sannivisto mattah smrtir jñanam apohanam ca: “I am seated in everyone’s heart, and from Me come remembrance, knowledge and forgetfulness.” From within, the Lord gives the living being the intelligence with which to work. Therefore the previous verse said that after the Supreme Personality of Godhead endeavors, our endeavors begin. We cannot independently endeavor or act upon anything. Therefore the Lord is bhuta-bhavanah.
Another specific feature of the knowledge given in this verse is that sabda-brahma is also a form of the Supreme Lord. In His eternal, blissful form, Lord Krsna is accepted by Arjuna as param brahma. A living entity in the conditioned stage accepts something illusory as substantial. This is called maya or avidya — ignorance. Therefore according to the Vedic knowledge, one must become a devotee, and one must then distinguish between avidya and vidya, which are elaborately explained in the Isopanisad. When one is actually on the platform of vidya, he can personally understand the Personality of Godhead in His forms like those of Lord Rama, Lord Krsna and Sankarsana. The Vedic knowledge is described as the breathing of the Supreme Lord, and activities begin on the basis of Vedic knowledge. Therefore the Lord says that when He endeavors or breathes, the material universes come into existence, and various activities gradually develop. The Lord says in Bhagavad-gita, pranavah sarva-vedesu: “I am the syllable om in all the Vedic mantras.” Vedic knowledge begins with the vibration of the transcendental sound pranava, omkara. The same transcendental sound is Hare Krsna, Hare Krsna, Krsna Krsna, Hare Hare/ Hare Rama, Hare Rama, Rama Rama, Hare Hare. Abhinnatvan nama-naminoh: there is no difference between the holy name of the Lord and the Lord Himself.