As is understood by the Quranic statement of »Allah guideth unto His light whom He will«, and traditions in the field, the main purpose of light is guidance; other meanings mentioned for it are secondary and return to it. The Exalted God`s purpose in mentioning niche, lamp and glass with many meanings, is to exemplify the manner in which God issues His Light. As the point is perceived from: »And Allah speaketh to mankind in allegories« also. Intensity of light of the lamp and the niche is understood by: »The glass is as it were a shining star«, »kindled from a blessed tree an olive neither of the East nor of the West«, »whose oil would almost glow forth (of itself) though no fire touched it« and »Light upon light«.