Srimad Bhagavatam Canto 10, Chapter 87, Text 15

SB 10.87.15

brhad upalabdham etad avayanty avasesataya
 yata udayastam-ayau vikrter mrdi vavikrtat
ata rsayo dadhus tvayi mano-vacanacaritam
 katham ayatha bhavanti bhuvi datta-padani nrnam
This perceivable world is identified with the Supreme because the Supreme Brahman is the ultimate foundation of all existence, remaining unchanged as all created things are generated from it and at last dissolved into it, just as clay remains unchanged by the products made from it and again merged with it. Thus it is toward You alone that the Vedic sages direct all their thoughts, words and acts. After all, how can the footsteps of men fail to touch the earth on which they live?
There may be some doubt as to whether the Vedic mantras are unanimous when identifying the Supreme Personality of Godhead. After all, some mantras state, indro yato ’vasitasya raja: “Indra is the King of all moving and nonmoving beings” (Rg Veda 1.32.15), while others say, agnir murdha divah: “Agni is the chief of the heavens,” and yet other mantras point to different deities as the Absolute. It would seem, then, that the Vedas present a polytheistic world view.
Answering this doubt, the Vedas themselves explain in this verse that there can be only one source of universal creation, called Brahman or Brhat, “the greatest,” which is the singular truth underlying and pervading all existence. No finite deity like Indra or Agni can fulfill this unique role, nor would the srutis be so ignorant as to propose such an idea. As indicated here by the word tvayi, Lord Visnu alone is the Absolute Truth. Indra and other demigods may be glorified in various ways, but they possess only those powers Lord Sri Visnu has granted them.
The Vedic sages understand that this entire world — including Indra, Agni, and everything else perceivable by the eyes, ears and other senses — is identical with the one Supreme Truth, the Personality of Godhead, who is called Brhat, “the greatest,” because He is avasesa, “the ultimate substance that remains.” From the Lord everything expands at creation, and into Him everything dissolves at annihilation. He exists before and after the material manifestation as the constant basis, known to philosophers as the “ingredient cause,” upadana. Despite the fact that countless manifestations emanate from Him, the Supreme Lord exists eternally unchanged — an idea the srutis specifically emphasize here with the word avikrtat.
The words mrdi va (“as in the case of clay”) allude to a famous analogy spoken by Udalaka to his son Svetaketu in the Chandogya Upanisad (6.4.1): vacarambhanam vikaro namadheyam mrttikety eva satyam. “The objects of the material world exist merely as names, transformations defined by language, whereas the ingredient cause, like the clay from which pots are made, is the actual reality.” A mass of clay is the ingredient cause of various pots, statues and so on, but the clay itself remains in its essence unchanged. Eventually, the pots and other objects will be destroyed and return to the clay from which they came. Similarly, the Supreme Lord is the total ingredient cause, yet He remains eternally untouched by transformation. This is the purport of the statement sarvam khalv idam brahma: “Everything is Brahman.” (Chandogya Upanisad 3.14.1) Wondering at this mystery, the great devotee Gajendra prayed,
namo namas te ’khila-karanaya
“Obeisances again and again to You, the source of all creation. You are the inconceivable cause of all causes, and of You there is no other cause.” (Bhag. 8.3.15)
Prakrti, material nature, is often considered the ingredient cause of creation, in Western science as well as in the Vedas. This does not contradict the higher fact of the Supreme Lord’s being the final cause, since prakrti is His energy, and is herself subject to change. In Srimad-Bhagavatam (11.24.19), Lord Krsna says:
prakrtir yasyopadanam
 adharah purusah parah
sato ’bhivyañjakah kalo
 brahma tat tritayam tv aham
“The material universe is real, having prakrti as its original ingredient and final state. Lord Maha-Visnu is the resting place of nature, which becomes manifest by the power of time. Thus nature, the almighty Visnu and time are not different from Me, the Supreme Absolute Truth.” Prakrti, however, undergoes transformation, while her Lord, the supreme purusa, does not. Prakrti is the Personality of Godhead’s external energy, but He has another energy — His internal energy — which is svarupa-bhuta, nondifferent from His very essence. The Lord’s internal energy, like Himself, is never subject to material change.
Therefore the mantras of the Vedas, along with the rsis who have received these mantras in meditation and transmitted them for the benefit of mankind, direct their attention primarily toward the Personality of Godhead. The Vedic sages direct the activities of their mind and words — that is to say, the inner as well as the literal meaning (abhidha-vrtti) of their utterances — first of all toward Him, and only secondarily toward separated transformations of prakrti, such as Indra and other demigods.
Just as a man’s footsteps, whether placed on mud, stone or bricks, cannot fail to touch the surface of the earth, so whatever the Vedas discuss within the realm of material generation, they relate to the Absolute Truth. Mundane literature describes limited phenomena, disregarding the relation of its subjects to the total reality, but the Vedas always focus their perfect vision on the Supreme. As the Chandogya Upanisad affirms in its statements mrttikety eva satyam and sarvam khalv idam brahma, reality is understood properly when everything is seen to be dependent on Brahman, the Absolute, for its existence. Brahman alone is real, not because nothing we see in this world is real, but because Brahman is the absolute, final cause of everything. Thus the word satyam, as used in the phrase mrttikety eva satyam, has been defined in another context as “ingredient cause” by no less an authority than Lord Krsna Himself:
yad upadaya purvas tu
 bhavo vikurute param
adir anto yada yasya
 tat satyam abhidhiyate
“A material object, itself composed of an essential ingredient, creates another material object through transformation. In this way one created object becomes the cause and basis of another created object. A particular thing may be called real in that it possesses the basic nature of another object that constitutes its cause and original state.” (Bhag. 11.24.18)
Explaining the word Brahman, Srila Prabhupada writes in Krsna, the Supreme Personality of Godhead: “The word Brahman indicates the greatest of all and the maintainer of everything. The impersonalists are attracted by the greatness of the sky, but because of their poor fund of knowledge they are not attracted by the greatness of Krsna. In our practical life, however, we are attracted by the greatness of a person and not by the greatness of a big mountain. Actually the term Brahman actually applies to Krsna only; therefore in the Bhagavad-gita Arjuna admitted that Lord Krsna is the Parabrahman, or the supreme rest of everything.
“Krsna is the Supreme Brahman because of His unlimited knowledge unlimited potencies, unlimited strength, unlimited influence, unlimited beauty and unlimited renunciation. Therefore the word Brahman can be applied to Krsna only. Arjuna affirms that because the impersonal Brahman is the effulgence emanating as rays of Krsna’s transcendental body, Krsna is the Parabrahman. Everything is resting on Brahman, but Brahman itself is resting on Krsna. Therefore Krsna is the ultimate Brahman, or Parabrahman. The material elements are accepted as inferior energy of Krsna because by their interaction the cosmic manifestation takes place, rests on Krsna, and after dissolution again enters into the body of Krsna as His subtle energy. Krsna is therefore the cause of both manifestation and dissolution.”
In summary, Srila Sridhara Svami prays:
 jagad idam na bhavet prthag utthitam
bahu-mukhair api mantra-ganair ajas
 tvam uru-murtir ato vinigadyase
“The demigods, headed by Siva, Agni, Surya and Indra, and indeed all beings in the universe, do not come into existence independently of You. The mantras of the Vedas, though they speak from various viewpoints, all speak about You, the unborn Lord appearing in numerous forms.”
Srimad Bhagavatam Canto 10, Chapter 87, Text 14
Srimad Bhagavatam Canto 10, Chapter 87, Text 16