From the Ribhu Gita.
10. Then, addressing Nidagha, Ribhu said: I shall tell you about the definition of the Self, which is not available in all the triad of time–past, present, and future–
11. ever the most secret of the secret, by summarizing what has been expounded by Siva. There is nothing that can be talked of as non-Self, neither the mind as the non-Self, nor the world as the non-Self. Be of the certitude that there is nothing that is non-Self.
12. By the absence of all sankalpas, by the elimination of all forms, by the conviction of there being only Brahman, be of the certitude that there is not anything that is non- Self.
13. In the absence of mind, there is no thinking; in the absence of the body, there is no aging. With the conviction of there being only Brahman, be of the certitude that there is no non-Self.
(mañana en español)