Ja'far al-Sadiq refers to it as a scroll (ṣaḥīfa) that is 70 cubits long and was dictated by the Islamic prophet Muhammad and written down by Ali.
Abd Allah ibn Shubruma, a jurist from Kufa who died in 144/761, is thus disparaged by Ja'far al-Sadiq.
Similar to this, Ja'far al-Sadiq claims that Abd Allah ibn Al-Hasan, a leader of the rival Shi'i Hasanid branch, only has access to the texts that are available to the rest of the community; he lacks the additional texts that the Imams possess and will not be able to respond to legal questions as a result.
Ja'far al-Sadiq is said to have buried the book when the extremist Shi'i al-Mughīra ibn Sa'īd was crucified in 119 (Hijri)/737-6(Gregorian) on the orders of the Umayyad governor Khalid al-Qasri, an event that al-Sadiq must have perceived as posing a threat to other Shi'is as well.
[11] The Twelver Shia believe that Al-Jamia is currently in the possession of the 12th Imam Muhammad al-Mahdi, after he inherited it from his predecessors.