Bhagwad Gita - Post 135

Verse 38

Twamaadidevah purushah puraanas

Twamasya vishwasya param nidhaanam;

Vettaasi vedyam cha param cha dhaama

Twayaa tatam vishwamanantaroopa.

Thou art the primal God, the ancient Purusha, the supreme refuge of this universe, the knower, the knowable and the supreme abode. By Thee is the universe pervaded, O Being of infinite forms!

After experiencing the cosmic vision in its true spirit, Arjuna prostrates and declares  this verse on the basis of his personal subjective experience. 

YOU ARE THE PRIMAL GOD - Tvam ādidevaḥ - “The Original Ancient one, the God of gods, Thou art.” 

Puruṣaḥ purāṇas: “The ancient Purusha, Purushottama, Narayana.” 

The Self or Brahman is the Supreme Creator. risen. The Self, conditioned by Its own creative urge, plays the part of the Creator.

YOU ARE THE SUPREME ABODE OF THE UNIVERSE -The entire Viswa is housed in the Lord, and therefore, it is said that the Lord is the Abode for the Universe. 

The  term Viswa includes the entire world of perceptions and the whole field of emotions and the total realms of thought that we, as intelligent individuals, experience in all our lives. This totality of the world of experience through the body, mind and intellect together is indicated by the term Vishwa.

THOU ART THE KNOWER AND THE KNOWABLE --- Vettāsi vedyaṁ ca paraṁ ca dhāma: “Thou knowest everything, whatever is to be known, because in Thy knowing Thyself, everything has already been known. 

The Supreme Abode is already attained in the vision of Thy Great Form. Thou art all things, spreading Thyself everywhere, O Visva Anantarupa, O All-formed One!” 

The Awareness in us is the Factor that completes all our experiences as realities. If the Light of Awareness were not to illumine the inert world-of-matter, no knowledge would have been possible, and therefore, the Principle of Consciousness, represented here as Lord Krishna, the Charioteer --- is described here as the Knower. 

The knower referred here is that pure consciousness which illumines the entire creation

The knowable referred here is not any object to be known but the supreme goal of human birth, the realization of SELF.

Hence, in this context, it is explained that the Lord / SELF is that which illumines the creation as much as it illumines a jiva, to proceed in the path of Spiritual Sadhana to ultimately realize that the goal which had to be attained, the knowable, is He himself (He the pure self, not He the body mind ego).

YOU PERVADE THE ENTIRE UNIVERSE OF FORMS --- Tvam asya viśvasya paraṁ nidhānam: “The very support and life-breath of this universe, Thou art. Who can know You except Yourself?” 

The superimpositions cannot exist apart from the Substratum upon which they are being perceived. 

A post or a pillar mistaken as  ghost, but the truth is that without the substratum Post, no one has the possibility to mistake it as a ghost. 

Waves, when they rise, may be taken as real, but for the waves to rise, stay and recede and die, the  substratum is water / ocean.

The Self is the Substratum on which the multitude of the world-of-plurality is visualized, and therefore, it is rightly said that "HE PERVADES ALL." 

This is only a repetition of the great Upanishadic Truth that "the Infinite pervades all, and nothing pervades It."

Love.