In Qurb al–Isnad ...
In Qurb al–Isnad , Abdullah al–Himyari observes: “Al–Qasim ibn Muhammad ibn Abu Bakr and Sai’d ibn al–Musayyab were once mentioned in the presence of al–Ridha’ peace be upon him who said: ‘They were on this affair’ meaning that they were Shi’ah.” In Al–Kafi in the chapter about the birth of Abu Abdullah al–Sadiq, Al–Kulayni relates: “From Yahya ibn Jarir who said ‘Abu Abdillah al–Sadiq said: Sai’d ibn al–Musayyab, al–Qasim ibn Muhammad ibn Abu Bakr and Abu Khalid al–Kabuli were among the people whom Ali ibn al–Husayn trusted.’ They are also said to be among the disciples ( hawari ) of Ali ibn al–Husayn (‘a).
Section Two: The Famous Jurists Among the Shi’ah of the very Early Period In his Rijal , Sheikh Abu Amr al–Kashshi, who was contemporary with Abu Jafar al–Kulayni, has considered the jurists among the companions of Abu Ja’far and Abu Abdillah (‘a) to be among the scholars of the third century. Naming them, he wrote: Our scholars were unanimous in regard to the truthfulness of these early companions of Abu Ja’far and Abu Abdillah (‘a) and they regarded them as great jurists.
They say: There are six foremost jurists of the earlier generations: Zurarah, Ma’ruf ibn Kharbudh, Buraid, Abu Basir al–Asadi, Al–Fudayl ibn Yasar and Muhammad ibn Muslim al–Ta'ifi, Zurarah being the most well–versed of them in jurisprudence. In place of Abu Basir al–Asadi, some mention Abu Basir al–Muradi whose full name was Laith ibn al–Bukhtiri.
Then he adds “In mentioning the names of jurists from among the companions of Abu Abdillah al–Sadiq (‘a) scholars are unanimous that whatever is reported from these jurists is authentic. They regard their word as credible and they acknowledge their competence in jurisprudence. There are also six others like those whom we previously named. They are Jamil ibn Darraj, Abdullah ibn Maskan, Abdullah ibn Bukayr, Hammad ibn Isa, Hammad ibn Uthman and Iban ibn Uthman.
Abu Ishaq al–Faqih Thalaba ibn Maimun claims that the most competent of them was Jamil ibn Darraj. They were among the youthful narrators and companions of Abu Abdillah (‘a).” Then al–Kishshi adds: “As for the jurists among the disciples of Abu Ibrahim (al–Kazim) and Abu al–Hasan (al–Ridha’) (peace be on them) our companions unanimously regard that which is definitely reported from them as authentic, believe in their integrity and acknowledge their competence in jurisprudence and learning.