“Two winged birds cling about a common tree, comrades, yoke-fellows; and one eats the sweet fruit of the true, the other eats not, but watches. The Soul upon a common tree is absorbed and because he is not lord, grieves and is bewildered; but when he sees and cleaves to that other who is the Lord, he knows that all is His greatness and his sorrow passes away from him.” Shwetashwatara Upanishad, IV. 6-7
“He who being One enters every womb and in whom all this comes together and goes apart, the adorable Godhead who rules as lord and gives us our desirable boons, one having seen comes exceedingly unto this peace.” Shwetashwatara Upanishad, IV.11
The unifying concept that accepts the unmoving and the moving as two aspects of a greater Divine Being, in Oneness, is called by some “integral non-dualism”. This integrative concept bridges the apparent separation and division, set up by the limitations of our mental process, between the silent, calm, uninvolved aspect of Existence sought after by those who follow the path of knowledge, and the involved, active life of those who follow the ways of devotion and works.
Sri Aurobindo describes the Gita’s view on this question: “The many-sided action of Nature is still possible even when the soul is poised in that calm self-existence: for the witness soul is the immutable Purusha, and Purusha has always some relation with Prakriti. But now the reason of this double aspect of silence and of activity is revealed in its entire significance,–because the silent all-pervading Self is only one side of the truth of the divine being. He who pervades the world as the one unchanging self that supports all its mutations, is equally the Godhead in man, the Lord in the heart of every creature, the conscient Cause and Master of all our subjective becoming and all our inward-taking and outward-going objectivised action. The Ishwara of the Yogins is one with the Brahman of the seeker of knowledge, one supreme and universal Spirit, one supreme and universal Godhead.”
Sri Aurobindo, Essays on the Gita, Second Series, Part I, Chapter 7, The Supreme Word of the Gita, pp. 327-328
and Sri Aurobindo, The Upanishads , Shwetashwatara Upanishad, Brahmanandavalli, Chapter 4, pp. 370-371, verses 6-7, 11