So, sloka 3 in Kena Upanishad answers the question but answers it in such a way that you cannot consider it to be an answer. Because one must find out, and not be spoon-fed. Any kind of spoon-fed knowledge is second-hand information that has nothing much to do with myself, therefore, is of no use to me, especially regarding my own Self. So, therefore, sloka 3 says Na tatra caksur gacchati na vag gacchati no manah. That which we are speaking about—that self, the ‘who’—who is behind all this that’s going on, who is the chief of the circus that’s going on; that self, can we reach it? Yes and no.
Why ‘no’? Because, Na tatra caksur gacchati na vag gacchati no manah. There, that neither the eye can see, that the eye cannot reach—‘na vag gacchati’—nor can there be a proper verbal description of it, because it defeats all descriptions; because it is the description-less supreme reality; because it is the definition-less supreme reality which cannot be defined by any words when one has found it. Therefore, one cannot define such a being.