This is a reference to an example of some of Jaʿfar al-Ṣādiq's senior disciples holding their own legal views and interpretations, such as Zurāra b. Aʿyan. Hossein Modarressi cites this reference in his discussion of some of the features of al-Ṣādiq's circle of disciples.
This source is part of the Online Companion to Hossein Modarressi, Text and Interpretation: Imam Jaʿfar al-Ṣādiq and His Legacy in Islamic Law (Harvard University Press, 2022).