Letters, symbols, and speech serve for conveying spiritual knowledge, and attainment. Every letter of every alphabet contains its spiritual meaning because people convey their sensations through books. Any sensation, not only human but animal as well, represents an unconscious perception of the Creator. Nobody understands this, but in reality when a poet for example, composes a verse portraying his love for a woman, children, the sun, light, or even in describing his suffering, he is expressing his impressions of the light that acts upon him, whether he wants it or not.
Courtesy of http://www.youtube.com/watch?v=MEskpfHOTAk