By Allah...
By Allah, if you ask me about anything that could happen up to the Day of Judgment, I will tell you about it. Ask me, for, by Allah, you will not be able to ask me a question about anything without my informing you.
Ask me about the Book of Allah, for by Allah, there is no verse about which I do not know whether it was sent down at night or during the day, or whether it was revealed on a plain or in a mountain.” (12) Sa’id Ibn Musayyib as well as Umar Ibn al-Khattab said: “No companion of the Prophet ever said ‘Ask me’ except Ali.” (13) Based on this, it can be said that “he who possesses the Knowledge of the Book” in verse 13:43 refers to Imam Ali (AS) and no other .
And if “a part of Knowledge of the Book” , provided a supernatural power for Asaf, then it is clear that those who have the whole knowledge of the Book, have more ability of this type by leave of Allah. Also according to the above tradition written in Sihah Sittah, in which the Prophet (PBUHH) said “I am the City of Knowledge, and Ali is its Gate.
So whoever intends to enter the City and the Wisdom, he should enter from its Gate”, it is clear that the only source of knowledge after (PBUHH) was Imam Ali (AS), and those who seek other sources do not gain the genuine Sunnah of the Prophet because nobody can enter this City from a direction other than its door.
Concluding Remarks It should be emphasized that The Twelver believe that neither the Prophet nor the Imams possess the Knowledge of Ghayb with the special meaning used in the Quran since this type of knowledge is something which belongs to Allah only. However, as Quran mentions “news of Ghayb” have been transmitted to the , and from that channel, it has been transmitted to the Imams of Ahlul-Bayt. What they fully possess is the Knowledge of the Book described above.
It should also be noted that the prophets and Imams share with the rest of humanity the means for obtaining knowledge which Allah has given: the senses, the intellect, etc. They also possess special powers and means that other people do not have. In carrying out the commands of Allah in which people have also responsibility, and likewise in ordinary behaviour, the Prophets and Imams only make use of the first way of knowing, which is the commonly available means.
The second means (extraordinary means) is only used by them in duties and works which are connected with their position of prophethood and Imamat.