Apparently you can't understand what you read. Gaudapada in Mandukya Karika, 4.99; “naitad buddhena bhasitam” (this was not expressed by Buddha).
Shankara comments: The nature of the supreme reality is free from the differences of knowledge, known and knower, and is without a second, etat, the fact: na bhâsitam, was not expressed; buddhena, by Buddha; though a near approach to non-dualism was implied in his negation of outer objects and his imagination of everything as mere consciousness. But this non-duality, the essence of the ultimate Reality, is to be known from the Upanishads only. This is the purport.
