There is a story in the Srimad Bhagavata about Krishna eating mud. One day while little Krishna was playing with Balarama and the other cowherd boys, he picked up a little bit of soil from the wet earth under his feet and put it into his mouth. Balarama and the other boys ran to Yashoda and complained about this.
Yashoda ran up to little Krishna and scolded him saying “Why did you do this? Why do you eat mud stealthily?” Krishna stood with tears rolling down his cheeks and told her “They are lying. I did not eat mud, mother. If you think I am lying and they are telling the truth, please look into my mouth” When he opened his mouth, the story goes that Yashoda saw within Krishna’s mouth the entire Universe – a microcosm of the macrocosm… the moving and the unmoving entities – the galaxies, the planets, stars, suns, cycle of constant creation and destruction, birth and death, the arrows of time, the individual, primeval, and supreme consciousness pervading, impregnating, and invading all sentient and insentient beings…
For a moment, Yashoda was stunned and too shaken to say anything –
Many of us have had these moments when a little bit of the spirit descends on us – the sudden tearing-up of the eyes, an involuntary shudder, a “disquieting quietness” that cannot be explained…
Sri Aurobindo captures this evocatively in the first few lines of his “The Hour of God“
“There are moments when the Spirit moves among men and the breath of the Lord is abroad on the waters of our being; there are others when it retires and men are left to act in the strength or weakness of their own egoism…“
Even before she could register what was happening, Krishna closed his mouth and the moment was gone she was his mother again and he her dear son…
There are four (4) Mahavakyas (Great Statements) from each of the 4 vedas that occur in each of their associated Upanishads that define and summarize the quintessence of vedantic thought and are relevant to this story. These four statements indicate the unity between the individual (consciousness) and the universal (consciousness) as experienced by Yashoda:
प्रज्ञानम् ब्रह्म “Pragnyanam Brahma” – “Conscious-Intelligence is Brahman” [Aitareya Upanishad; 3.3 of Rig Veda]
अहम् ब्रह्मास्मि “Aham Brahm-asmi – “I am that Brahman. Atman / Conscious-Intelligence / integrated part of that universal consciousness” [Brihadaranyaka Upanishad; 1.4.10 of Yajur Veda]
तत् त्वम् असि “Tat-tvam Asi” – “You are that (Brahman)” [Chandogya Upanishad; 6.8.7 of Sama Veda]
अयम् आत्मा ब्रह्म “Ayam Aatma Brahma” – This self, this atman is that Brahman / Supreme Consciousness [Mandukya Upanishad; 1.2 of the Atharva Veda]
These four statements could be examined or understood individually or as a graduated progression of the inner realization – I prefer the latter:
First the understanding that there is an Omniscient consciousness that pervades everything in the universe. Second a fragment of this consciousness is present in each sentient and insentient being and is Omnipresent. Finally, the realization that this omnipresent being is the atman which is a part of the supreme paramatman.