A narration (riwaya) does not require the same (acceptance)...

A narration (riwaya) does not require the same (acceptance) as definite knowledge (diraya)." The Basran could not find an answer to this and departed. However, al-Mufid took up the discussion: "O Shaykh, I have a problem," he said to 'Ali b. 'Isa. "Put it forward, then," replied the latter. "What would you say about someone who fought against a just Imam?" asked al-Mufid. "He is an unbeliever (kafir)," was the answer.

Then after a pause he changed it to "grave sinner (fasiq)." "What do you say about the Commander of the Faithful, 'Ali b. Abi Talib?" . He was an Imam." "What do you say about the Battle of the Camel, and some of the companions who fought against Ali b. Abi Talib." Therefore according to the above argument they should be described as fasiq, that is grave sinners who would go to hell.

(However there is a tradition that these companions were among ten people whom the Prophet said would go to heaven. Thus 'Ali b. 'Isa has to explain how they could be fasiq and go to heaven. He does this in his next answer.) "They repented." "The tradition of the Battle of the Camel is definite knowledge (diraya) while the tradition of the repentance is a narration (riwaya)," replied al-Mufid. Thus al-Mufid had turned the tables on him.

The event of the cave was something all Muslims accepted as fact but there was no point in giving the well-reported tradition of Ghadir Khumm inferior status since if this was done the same terminology could be used to question the repentance of the said companions, which was also accepted by most Muslims. 'Ali b. 'Isa was very impressed by the young man's reasoning. He asked him about his teacher and then gave him a note to take to that man.

In the note he recommended his intellect and gave him the nickname of al-Mufid, "the one who gives benefit". [^3] Al-Mufid soon became one of the foremost scholars of his time. He was an outstanding theologian and jurist, and a brilliant polemical writer on behalf of the Shi'ites. He became head of the Shi'i scholars in Baghdad and took part in many debates and discussions with his opponents. As we have seen there was some rivalry between various groups during this period.

This rivalry became much more tense during the time of the four rival days of remembrance which all came within four weeks of each other. Riots sometimes broke out and the authorities had to take firm action to restore the situation. After such a riot in 398 A.H./1007, al-Mufid was nearly exiled from Baghdad.