6. Muhammad ibn Musa ibn Mutawakkil said: Muhammad ibn Yahya al-`Attar said, on the authority of Sahl ibn Ziyad, on the authority of `Amr ibn `Uthman, on the authority of Muhammad ibn Yahya al-Khazzaz, on the authority of Muhammad ibn Sama`ah, that Abu `Abd Allah al-Sadiq A(S) said:

The head of the rabbis [ra`s al-jalut] said to the Jews. “Verily, the Muslims consider Ali to be the greatest debater and the most learned one among them. Take me to him so that I may ask him a question that will confound him.” Hence, he came to him and asked: “O Commander of the Faithful! Since when has our Lord existed?” Ali replied:O Jewish man! It is certainly said: “When did it exist?” for something that previously did not exist. However, He has always existed, does exist, and will always exist forever. He has always existed, without quality. O Jewish man! How2 can He have a beginning? He is prior to the beginning, without a beginning, end [ghayah], and termination. He is the End and there is no end to Him. He is the End that is separate from all ends. He is the End of all Ends. Then the Jewish man said: “I bear witness that your religion is true, and that whatever contradicts it is false.”