The fifteenth chapter of the Bhagavad Gita is Purushottama Yoga. In Sanskrit, Purusha means the All-pervading God, and Purushottam means the timeless & transcendental aspect of God. Krishna reveals that the purpose of this Transcendental knowledge of the God is to detach ourselves from the bondage of the material world and to understand Krishna as the Supreme Divine Personality, who is the eternal controller and sustainer of the world. One who understands this Ultimate Truth surrenders to Him and engages in His devotional service.
And entering the earth I sustain the beings through (My) power; and nourish all the plants by becoming Soma which is of the nature of sap.OPEN VERSE
Taking the form of Vaisvanara and residing in the bodies of creatures, I, in association with Prana and Apana, digest the four kinds of food.OPEN VERSE
And I am seated in the hearts of all. From Me are memory, knowledge and their loss. I alone am the object to be known through all the Vedas; I am also the originator of the Vedanta, and I Myself am the knower of the Vedas.OPEN VERSE
There are these two persons in the world-the mutable and the immutable. The mutable consists of all things; the one existing as Maya is called the immutable.OPEN VERSE
But different is the supreme Person who is spoken of as the transcendental Self, who, permeating the three worlds, upholds (them), and is the imperishable God.OPEN VERSE