Once Abu Khalid Kabuli asked Imam Muhammad Baqir (a.s) about the meaning of “Light” in the verse:
Therefore believe in Allah and His Apostle and the Light, which We have revealed. (Surah Taghabun 64:8)
Imam (a.s) replied, “It denotes us, the Imams. By Allah, only we are the light of Allah that have descended from Him and only we are the light of Allah in the heavens and the earth as mentioned in the verse:
Allah is the light of the heavens and the earth. (Surah Nur 24:35)
Imam (a.s) further said: When the verse:
(Remember) the day when We will call every people with their Imam… (Surah Bani Israel 17:71)
was revealed, people asked the Messenger of Allah (S), “Are you not the Imam of all the people?” The Prophet replied, “I am the Prophet for all the people till Qiyamat, but there would be Imams from my progeny, who would be appointed by Allah like I am. But the misguided people would consider them liars. They would oppress them and their followers. Only these people (Imams) are from me and only they would be with me in Paradise on the Day of Judgment. And those who have oppressed them and their followers would remain away from me.”
Reference :Akhlaq al-A’imma, Morals & Manners of the Holy Imams