Ali ibn Mohammad and Mohammad ibn al-Hassan have narrated from Sahl ibn Ziyad from Mohammad ibn al-Hassan ibn Shammun from ‘Abd Allah ibn ‘Abd al-Rahman al-Asamm from ‘Abd Allah ibn al-Qasim from Salih ibn Sahl al-Hamadani who has said the following: “Abu ‘Abd Allah(عليه السلام) has said the following about the statement of Allah, the Most High, ‘Allah is the light of the heavens and the earth. A metaphor for His light is a lantern in which there is a lamp placed in a glass. The glass is like a shining star, which is lit from a blessed olive tree that is neither eastern nor western. Its oil almost lights up even though the fire has not touched it. It is light upon light. Allah guides to His light whoever He wants. Allah uses various metaphors. He has the knowledge of all things.’ [24:35] The Imam said, “Lantern” metaphorically stands for the Holy lady, Fatimah(عليها السلام) the “Lamp” stands for Imam al-Hassan(عليه السلام) and “the glass” stands for Imam al-Husayn(عليه السلام) “The shining star” stands for the Holy lady Fatimah(عليها السلام) who shines among the ladies of the world. “The blessed olive tree” stands for Prophet Abraham. “Neither eastern nor western” means not Jewish nor Christian. The expression: “Its oil almost lights up” means that it almost bursts up with knowledge. “Light upon light” means that there will be one Imam after the other Imam(عليهم السلام) “Allah guides to His light whoever He wants” means that Allah guides through the ‘A’immah (plural of Imam) whoever He wants.’ About the expression “Allah uses various metaphors” I then recited the following verse of the Holy Quran: ‘Or they (the deeds of the unbelievers) are like the darkness of a deep, stormy sea with layers of giant waves, covered by dark clouds. It is darkness upon darkness whereby even if one stretches out his hands he cannot see them. One can have no light unless Allah gives him light.’ [24:40]
“The Imam(عليه السلام) said, ‘The word “Darkness” refers to the first(i.e. Abu Bakr) and his friend(i.e. Umar), the expression “With layers of giant waves” refers to the third(i.e. Uthman), and the expression “Covered with darkness” refers to the second(i.e. Umar). The words “It is darkness upon darkness” refer to Mu‘awiya (may Allah condemn him) and the disasters caused by the Umayvids. The phrase “Even if one stretches out his hands” means that even if a true believer stretches out his hands in such disastrous condition “he cannot see them.” The statement “One can have no light unless Allah gives him light” stands for the light from the children of the Holy lady, Fatimah(عليها السلام). The phrase “Can have no light” means an Imam on the Day of Judgment. The Imam(عليه السلام) said that, ‘On the Day of Judgment you will see the believers with their light shining in front of them and to their right. They will be told, ‘Paradise wherein streams flow is the glad news for you today. You will live therein forever. This is the greatest triumph.’ [57:12] The phrase “The shining light in front . . . ” is a reference to the Imam(عليه السلام) who will walk in front and on the right of the true believers until they all enter paradise.’”
Ali ibn Mohammad and Mohammad ibn al-Hassan have narrated from Sahl ibn Ziyad from Musa ibn al-Qasim al-Bajali and Mohammad ibn Yahya from al-‘Amraky ibn Ali altogether from Ali ibn Ja‘far from his brother Imam Musa Al-Kadhim(عليه السلام) a similar Hadith.
Grading: Sahih(authentic).
The narrators of one of the three chains are trustworthy, check the Rijaal section:
1819: Mohammad Ibn Yahya Al-Attaar Al-Qummi
1362: Al-Amraki Ibn Ali Al-Bufaki
1216: Ali Ibn Ja'far As-Sadiq(عليه السلام)
Source: Usul Al-Kafi, Vol.1, Pg. 115, Book of Hujja, chapter 70