The teacher, however, warns the disciple that this eye, ear, mind, can never perceive It; for It is that which illumines speech and mind, which enables eye and ear and all sense-faculties to perform their tasks. "It is distinct from the known and also It is beyond the unknown." He who thinks he knows It, knows It not; because It is never known by those who believe that It can be grasped by the intellect or by the senses; but It can be known by him who knows It as the basis of all consciousness.
The knower of Truth says, "I know It not," because he realizes the unbounded, infinite nature of the Supreme. "Thou art this (the visible), Thou art That (the invisible), and Thou art all that is beyond," he declares. The ordinary idea of knowledge is that which is based on sense preceptions; but the knowledge of an illumined Sage is not confined to his senses. He has all the knowledge that comes from the senses and all that comes from Spirit.
The special purpose of this Upanishad is to give us the knowledge of the Real, that we may not come under the dominion of the ego by identifying ourselves with our body, mind and senses. Mortals become mortals because they fall under the sway of ego and depend on their own limited physical and mental strength. The lesson of the parable of the Devas and Brahman is that there is no real power, no real doer except God. He is the eye of the eye, the ear of the ear; and eyes, ears, and all our faculties have no power independent of Him. When we thus realize Him as the underlying Reality of our being, we transcend death and become immortal.
OM! PEACE! PEACE! PEACE!