"Create in me a clean heart, Elohim ..."
Rabbi Yehuda begins a discussion of the steadfast spirit of Messiah, which King David invoked to preserve himself from the spirit of confusion, whose task is leading people astray. Rabbi Yosi and Rabbi Elazar then discuss in some detail Ahab's crime against Navot, along with the verse, "the lying spirit in the mouth of the prophets." This spirit was not that of Navot, as has been presumed, but rather, the lying spirit which continually ascends and descends to distract people from life's true goal. King David, because he knew full well the rewards of the righteous, often made supplication in order that he might be guarded from defilement by powerful Accusers of this world.
Far worse than lying to others is the act of lying to ourselves. It is in our nature to believe our own false tales and then attempt to promote these distortions in the world. Self-deception is the greatest of all deceptions, because our intentions might very well be good. When sunlight shines through the window pain, the dust floating in the air is suddenly revealed. Spiritual Light has the same effect on our negative qualities, which so often remain hidden. Purposefully perusing these passages removes prevarication, so that the true purpose of our existence - identifying and eliminating negative aspects of our character - shines brightly in our lives. It is of equivalent effect to David's supplications, summoning the Light to guard us from the ever-present dangers of self-deception, and allowing us to grow in righteousness and wisdom.