The Imams (a.s.) do have the knowledge of what was and will be, and that nothing is unknown to them (a.s.)

he with a group of Shi‘a were in the presence of abu ‘Abdallah (a.s.) in Hijr and the Imam (a.s.) said the following. “An eye is watching over us.” We then looked right and left and did not see anyone. We said, “No eye is watching over us.” The Imam (a.s.) said, “I swear by the Lord of the Ka‘ba. I swear by the Lord of the House.” He said so three times. “Had I been with Moses and al-Khidr I would have told them that I had more than they did and would have informed them of what they had no knowledge. This is because Moses and al-Khidr were given the knowledge of what was in the past and they were given the knowledge what will be in future or what will exist up to the Day of Judgment while we have inherited all of them from the Messenger of Allah as heirs.”

abu ‘Abdallah (a.s.) say the following. “I certainly know what is the heavens and what is in the earth. I know what is in paradise and what is the fire. I know what was there and what will be there.” The narrator has said that the Imam (a.s.) paused for a while and found that what he had just said was much heavy for the audience then he (a.s.) said, “I learned all of it from the book of Allah, the Most Holy, the Most High. Allah, the Most Holy, the Most High, has said, “In it there is the clarification of all things.”

al-Mufaddal was in the presence of abu ‘Abdallah (a.s.). Al-Mufaddal asked the Imam (a.s.) the following. “May Allah, take my soul in service for your cause, does Allah command (his) servants to obey a servant and hide the news of the heavens from him?” The Imam (a.s.) said, Allah is by far much honorable, kind and caring towards His servants than to command them to obey a servant (of His) and then hide form him the news of the heavens mornings and evenings.”

he heard abu Ja‘far (a.s.) the following to an audience of his companions: “What an strange case is the case with a group of followers! They acknowledge us as the Divine authority over themselves, accept us as their Imam and say that obedience to us is obligatory just as is the case with the Messenger of Allah (sw). They then destroy the veracity of their belief as such and dispute against their own selves due to weakness of their hearts. They then diminish our right and blame those whom Allah has granted evidence to know us as it should be and the (ability) to submit themselves to our Divine authority. Do you not consider that how would Allah, the Most Holy and Most High, make it obligatory to obey those who possess Divine authority over his servants and then hide from them (people who possess Divine authority) the news of the heavens and the earth? How would He cut them off of the sources of knowledge that might come to them to maintain their religion?”
Humran then said to the Imam (a.s.), “May Allah, take my soul in service for your cause, how would you explain the case of the uprising of Ali ibn abu Talib, al-Hassan and al-Husayn (a.s.)? They came out and rose up for the cause of Allah, Whose mention is so Majestic. How much they suffered and how mercilessly were they murdered at the hands of the rebels? They were defeated, murdered and over powered.” Abu Ja‘far (a.s.) then said, “O Humran, Allah, the Most Holy, the Most High, had determined it on them. He had decreed, approved and made it unavoidable though the voluntary manner. He then allowed to take place. It, thus, happened with a pre-existing knowledge that had come to them from the Messenger of Allah. Ali, al-Hassan and al-Husayn (a.s.) rose up for the cause of Allah with full knowledge of the consequences and remained silent from us those who remained silent. Had they, O Humran, when facing what Allah, the Most Holy, the Most High, made them to face and suffer defeat at the hands of the rebels, asked Allah, the Most Holy and Most High, to remove their suffering and would implore Him to destroy the government and kingdom of the rebels, He would have answered their prayers and would grant them relief. In such case the destruction of the governments of the rebels and the ending of their time would take place quicker than the dispersal under a great pressure, of beads threaded together. The suffering, O Humran, that befell them, was not due to sins they committed, nor was it a punishment for a disobedience in which they defied Allah. It was because of the high marvelous position that Allah had prepared and wanted them to reach. Do not let people’s opinions take you away from the right path.”

“I asked abu ‘Abdallah (a.s.) at Mina five hundred letters from al-Kalam (theology). I asked the Imam (a.s.), “They say that he has said so and so.” Then he says, “You say so and so.” I then said to the Imam (a.s.), “May Allah, take my soul in service for your cause, “This is lawful and that is not lawful. I know that you are the authority in this and you are the most knowledgeable person in it and this is al-Kalam.” The Imam (a.s.) said to me, “O poor, Hisham, Allah, the Most Holy, the Most High, does not require any duty from His creatures without first availing them all that they need to comply with the command.”

he heard abu Ja‘far (a.s.) say the following. “No, I swear by Allah, the scholar (who possesses Divine authority) is never ignorant or knowledgeable in something and ignorant of other things. The Imam (a.s.) then said, “Allah, the Most Holy, Most High and Most Gracious, is far exalted and above imposing the obedience of a servant (of His) on the others and then hide the knowledge of things in the heavens and on earth from him and then say, “Do not hide that from him.”