Abu Sahl Isma'il b. Ali al-Nawbakhti mentioned at the end of his book Al-Tanbih: Our opponents often say, “If what you claim about the designation (nass) were true, then Ali would have declared it after the death of the Prophet ﷺ.” We say to them: How could he declare it and put himself forward as someone making a claim that requires witnesses, when they had already rejected the Prophet’s ﷺ own words? How would they accept his? His refusal to pledge allegiance to Abu Bakr and his secret burial of Fatimah without informing the public are the clearest signs that he was not pleased with what they had done. And if they ask, “Why did he accept it after Uthman?” we say: He accepted a part of what was rightfully his, just as the Prophet ﷺ accepted the hypocrites and those whose hearts were inclined (to Islam).

And sometimes our opponents, when pressed by argument and forced to admit that there must be an Imam explicitly appointed, knowledgeable of the Qur'an and Sunnah, trustworthy and infallible, whose obedience is obligatory by clear designation, will say: “Then who is this Imam? Name him and show him to us.” We reply: This is now a matter of historical transmission, a different topic from what we were originally discussing- namely, what reason requires after the Prophet’s ﷺ passing. Once that necessity is established through proof, it becomes everyone’s responsibility to search for the Imam described. The Shia have transmitted the designation of Ali , and they are now so numerous and spread across lands and of such differing backgrounds that their collective testimony leads to certain knowledge and obligation- especially since there is no opposing group that claims designation for anyone other than Ali . And if they compare us to the followers of Zoroaster or others among the false claimants, we say: That objection would apply equally to the miracles of the Prophet ﷺ. If they have a response to defend those, then that response applies to us too.

In fact, the reports of the Shia are even more trustworthy, because they had no power, no government, no fear to impose, and no desire to bribe. False reports are usually spread because of greed, fear, or political pressure, but none of that applies to the Shia reports. So, if their transmission of the designation from the Prophet ﷺ to Ali is valid, then so is their transmission from Ali to Hasan, from Hasan to Husayn, and from each Imam to the next, up to al-Hasan b. Ali and the hidden Imam after him . The trustworthy companions of his father, al-Hasan , all testified to his Imamate. He went into occultation because the authorities were actively seeking him, assigning guards to his home and his family for two years. If I were to say that the occultation of the Imam in our time is itself among the strongest proofs of the truth of the Imamate, I would be speaking truthfully because of the reliability and fame of the earlier reports about it.

And some Shia who served al-Hasan b. Ali and were among his trusted men have narrated that they had a direct connection with the son of al-Hasan b. Ali , and that letters and commands would come through them to the Shia until that representative passed away. He then left instructions to another trustworthy Shia, who took over his role in this matter.