सर्वस्य चाहं हृदि सन्निविष्टो
मत्तः स्मृतिर्ज्ञानमपोहनं च ।
वेदैश्च सर्वैरहमेव वेद्यो
वेदान्तकृद्वेदविदेव चाहम् ॥ १५.१५ ॥

sarvasya cāham hṛdi sanniviṣṭo
matta: smṛtir-jñānam-apohanam ca |
vedaiś-ca sarvair-aham-eva vedyo
vedānta-kṛd-veda-vid-eva cāham || 15.15 ||

He now goes on to describe it as present within the body, even in the sphere of the mind and intelligence:

Supreme is embedded in all hearts, giving rise to memory, wisdom and forgetfulness. Four Vedas speak of the Supreme alone. The author as well as the Knower of Vedanta is again the Supreme.

The Supreme is closest to everyone, whether we admit it or not. It is present in everyone’s heart. To trace it functionally, Krishna lists memory (smṛti), knowledge (jñānam), and forgetfulness (apohanam), stating that all these emerge only from this indwelling Presence. These are conscious functions, reigning above the range of matter and energy.

He does not specify the memory as good, benign or virtuous. Memory is always the recollection of things transpired. Actions and events take place in the march of time. As they occur, so they pass off and what they leave is their memory. This survives only because of the Supreme presence in one.

Knowledge of any kind is also due to the Supreme. Forgetfulness too. Forgetfulness or its possibility is the ground on which memory rests. It is like friction to movement.

All the Vedas speak about and reveal one supreme Reality. Vedic hymns may be numerous, but the import of them all is but one, contained in their mahāvākyas – Prajñānam Brahma of Rgveda, Aham Brahmāsmi of Yajurveda, Tat-tvam-asi of Sāmaveda and Ayamātmā Brahma of Atharvaveda. All these describe Brahman alone. The first denoting its nature as ‘knowledge’, the second describing its locus as the ‘I’ in all, the third specifying the instruction to the seeker as “you are That”, and the fourth confirming that the inner Self alone is the supreme Reality.

All the Vedas, in the form of Knowledge, are but creations of this Supreme itself. The Knower of Vedas also is the Supreme. In other words, every individual identity is a reference to the Supreme. The entire knowledge is but its own display.

The Knower of Truth is the distinct expression of the Supreme. He alone, like Krishna, will be able to think, speak and act on Its behalf. The same idea Krishna has set forth earlier also: jñānī tu ātmaiva me matam (7.18). The supreme Reality is a spiritual concept. It is illustrated and explained by man alone. Other than the Knower, the supreme Reality has no representation at all.