The Illusory Nature of Perception

What truth does it illustrate when one's foot is bitten by a mosquito, feeling intensely itchy yet unable to pinpoint the exact location? And why, upon shifting attention to ponder a question, does the itchiness seem to disappear?

The tactile dust object (contact sensation) on the outer foot is transmitted into the supreme meaning faculty (indriya) and becomes an internal tactile dust object. The mental faculty (manas) and consciousness (mano-vijñāna) cognize the tactile dust object within the supreme meaning faculty but fail to clearly discern its precise location. Perhaps the transmission nerves are faulty, or perhaps the location was not transmitted clearly, or perhaps the manifestation is unclear, or perhaps the conscious mind fails to distinguish it clearly. In any case, the tactile dust object cognized by the sixth and seventh consciousnesses is not the true tactile sensation of the foot. Therefore, we need not overly concern ourselves with the forms, sounds, smells, tastes, tactile objects, and mental objects (dharmas) contacted by the seven consciousnesses, as they are all unreal and non-substantial dharmas. Moreover, the seven consciousnesses themselves are still unreal and non-substantial; the sensations and perceptions of the seven consciousnesses are equally unreal and non-substantial. Hence, consciousness, mental activities, sensations, and perceptions are not the self.

When the mental faculty and consciousness do not attend to (do not apply mental attention to) the internal tactile dust object of the foot, there is no clear sensation or perception. Therefore, upon shifting attention, the itchiness is no longer felt. This reveals the falsity and illusory nature of sensations and perceptions.