Chapter 15: Yoga of the Supreme Spirit; Purushottama Yoga
This a short chapter, including 20 slokas detailing the tree of Samsara, the nature of the Jiva, (the individual being), the subtle body and reincarnation. It further explains how to develop our mind to maturity, to experience them all illuminating light, perishable and the imperishable.
Verse 15: And I have entered the hearts of all. From Me (have come) memory, knowledge, and forgetfulness. I am alone the one to be known by all the Vedas and I alone am the author of the Vedaanta and the knower of the Vedas.