I asked Abu `Abd Allah al-Sadiq (AS): “Allah is the Light of the Heavens and the Earth?” He answered: “Such is Allah, the Mighty and High.” He says: I asked: “A likeness of His Light?” He answered: “Muhammad (sw).” I enquired: “As a niche?” He replied: “Muhammad (sw) chest.” I then asked: “In which is a lamp?” He said: “That of Prophethood, which contains the Light of Knowledge.” I asked: “The lamp is in a glass?” He answered: “The knowledge of the Messenger of Allah (sw) is preserved in `Ali’s heart.” I asked: “As if she were?” He asked: “Where did you get `As if she were?” So I said: “May I be your ransom! How should I read it?” He said: “As if it were a brightly shining star.” I then asked: “Lit fro a blessed olive-tree, neither eastern nor western?” He replied: “That is the Commander of the Faithful `Ali ibn Abu Talib (AS), who was neither Jewish nor Christian.” I asked: “The oil whereof almost gives light though fire touches it not?” He answered: “The knowledge more or less comes out of the mouth of the learned from the Progeny of Muhammad (AS) before they even speak.” I asked: “Light upon light?” He said: “An Imam (AS), one after another.”