Kaṭhopaniṣad 2.7-8—Hearing from the Adept

“Of that Self—which is not available for the mere hearing to many, and which many do not understand even while hearing—the expounder is wonderful and the receiver is wonderful; wonderful is he who knows, under the instruction of an adept. The Self is certainly not adequately known when spoken of by an inferior person; for It is thought of variously. When taught by one who has become identified with It, there is no further cogitation with regard to It. For It is beyond argumentation, being subtler even than the atoms.“