32-29 Muhammad ibn Ibrahim ibn Ishaq al-Taliqani - may God be pleased with him - narrated that Ahmad ibn Muhammad ibn Sa’eed al-Kufi quoted on the authority of Ali ibn Al-Hassan ibn Ali ibn Fadhdhal, on the authority of his father:

I asked Abal Hassan Ar-Ridha’ , “Why was the Prophet’s nickname Abul Qasim?” Ar-Ridha’ said, “It was because he had a son named Qasim. That was why his nickname was Abul Qasim.” I asked him, “O son of God’s Prophet (S)! Do you consider me worthy of more explanation?” Ar-Ridha’ said, “Yes. Don’t you know that God’s Prophet (S) said?, “Ali and I are the fathers of this nation.” I said, “Yes, I do.” Ar-Ridha’ said, “Don’t you know that God’s Prophet (S) is the father of all the nation, and Ali is one of the members of this nation?” I said, “Yes.” Ar-Ridha’ said, “Don’t you know that Ali is the ‘Qasim or the one who divides up Paradise and Hell?” I replied, “Yes.” Ar-Ridha’ said, “Then that is why the Prophet (S) is called Abul Qasim - as he is the father of the one who divides up Paradise and Hell.” I asked, “What does this mean?” Ar-Ridha’ replied, “The kindness of the Prophet (S) for his nation is like that of a father for his children. The noblest member of his nation is Ali . And after him the kindness of Ali for them is like the kindness of the Prophet (S), since he is the Prophet’s Trustee, Successor and the Divine Leader after the Prophet (S). That is why the Prophet (S) said, “Ali and I are the two fathers of this nation.” God’s Prophet (S) climbed up the pulpit and said, “Whoever leaves behind a debt or a wife, I must repay his debt and pay for the living expenses of his wife. Whoever leaves behind some property, that property will belong to his inheritors.” That is why the Prophet (S) was superior to their fathers, mothers and even themselves. The same thing held true for the Commander of the Faithful after God’s Prophet (S).”