The Eternal Brahman is concealed by flesh and bones. The appearance of the body hides away the Reality.
Truth is covered by a golden vessel.
The sun is very big in size, much bigger than the whole earth itself, but a finger over the eyes renders such a sun invisible. Brahman is Truth, Knowledge, Infinity, but a tiny force of Avidya which covers the self makes the entire Brahman imperceptible and even makes it to be felt as non-existing. The removal of the finger makes one behold the glorious sun. The eradication of thought allows one to experience the Infinite Reality. The perception of the unreality of the visible universe and everything which cannot be Brahman is one of the methods to seek the oneness of the self with Brahman or the Absolute.