Sri Aurobindo cites the Gita to provide a general sense of how all existences are contained within the Self-existent Being: “It is as the great, the all-pervading aerial principle dwells in the etheric that all existences dwell in Me, that is how you have to conceive of it…”
He goes on to explain this: “The universal existence is all-pervading and infinite and the Self-existent too is all pervading and infinite; but the self-existent infinity is stable, static, immutable, the universal is an all-pervading movement…. The Self is one, not many; but the universal expresses itself as all existence and is, as it seems, the sum of all existences. One is Being; the other is Power of Being which moves and creates and acts in the existence of the fundamental, supporting, immutable Spirit. The Self does not dwell in all these existences or in any of them; that is to say, he is not contained by any,–just as the ether here is not contained in any form, though all forms are derived ultimately from the ether. Nor is he contained in or constituted by all existences together–any more than the either is contained in the mobile extension of the aerial principle or is constituted by the sum of its forms or its forces.”
The principle here is that the Divine is not limited by the forms and is not simply a “sum of the parts”, as it were. The pervasion is spiritual and contains all forms while not being bound or contained by those forms. A clay pot is made of earth, but it does not limit earth beyond its own form. Before the clay pot exists, the earth exists. After the clay pot as a form goes out of existence, the earth continues to exist. The earth principle is larger than the clay pot, and is not limited by the form of clay pot for its existence. The principle of earth pervades the clay pot at all times, and no matter how many clay pots one forms, the earth principle still exceeds it.
Just as the earth principle permeates the clay pot, the universal Being permeates, but is not limited by any of the forms it takes on, or the movement it supports. There is “a truth of being in its all-containing immutability, self-existent….” and there is a “truth of Power of the same being manifest in the government and information of its own self-veiling and self-revealing movements.”
Sri Aurobindo, Essays on the Gita, Second Series, Part I, Chapter 5, The Divine Truth and Way, pp. 304-305