I am giving even this much of detail only to give you a sample of how men of intelligence
and scholarship have been wasting their talents, and yet not gaining the real benefits out of the study of the Upanishad-s.
To declare vaguely that Adi Sankaracharya had never quoted Mandukya in his Bhashya would be a very rough and ready method in this delicate operation.
In fact many great writers before Adi Sankaracharya had quoted the Upanishad-s claiming them to be from Mandukya; also in many places in his commentary we can smell the words of Swami Adi Sankaracharya as belching through a heart soaked with Mandukya - Ideas.
To be continued ....