One who knows does not say it; one who says does not know it. Block the openings, Shut the doors, Soften the glare, Follow along old wheel tracks; Blunt the point, Untangle the knots. This is known as dark identity. Thus you cannot get close to it, nor can you keep it at arms length; you cannot bestow benefit on it, nor can you do it harm; you cannot ennoble it, nor can you debase it. Hence it is the most valued.