"We can say, therefore, that this ultimate source, clear light, is close to the notion of a Creator, since all phenomena, whether they belong to samsara or nirvana, originate therein. But we must be careful in speaking of this source, we must not be led into error. I do not mean chat there exists somewhere, there, a sort of collective clear light, analogous to the non-Buddhist concept of Brahma as a substratum. We must not be inclined to deify this luminous space. We must understand that when we speak of ultimate or inherent clear light, we are speaking on an individual level." — His Holines the Dalai Lama
What the Dharmakaya Is
Dhamrakaya is Inherent clear light and the essential nature of the mind.
All phenomena experienced in samsara and nirvana, arise from "this clear and luminous source".
Thus, the inherent clear light == the clear and luminous source == Dharmakaya
Description of the practitioner of Great Yoga
"The state of rest" of a practitioner is "the state of the practitioner who has reached a stage in meditation where the most subtle experience of clear light has been realized".
Thus the state of rest refers to the mind at rest in the samadhi called "Great Yoga"
The Stage of the Ultimate Sphere
By implication the stage of ultimate sphere is a level of meditative experience.
This stage is known as "The ultimate sphere".
Two things happen to the practitioner who remains in the ultimate sphere. He or she
- "remains totally free of any sort of veil obscuring the mind", and
- "is immerse in a state of great bliss".
The Dalai Lama's answer on a Creator and Creation: http://hhdl.dharmakara.net/hhdlquotes22.html
Seven Virtues: http://en.wikipedia.org/wiki/Seven_virtues