Historically speaking...
Historically speaking, in the fourth/tenth century, with the emergence of a gradual weakness in Mu’tazila school and the start of consolidation of Ash’ari school, the field of narrations started to play major roles in theological matters and among the theological works within this narrative-inclined movement, probably the book al-Tawhid written by Ibn Khuzayma and the chapter al-Tawhid of al-Kafi were noteworthy to al-Saduq.
Reception by Shi’a Scholars Considering the background discussions about divine essence and attributes, and taking into account the narrative and theological Shi’a heritage and observing the effects of Sunni hadith movement, al-Shaykh al-Saduq started to compile al-Tawhid to deny the accusations of the belief in divine corporeality and predestination and to set forth foundations of Shi’a belief based on verses of the Qur’an and narrations.
About the historical position and the significance of this book, in addition to what has already been said, one must take into account the status of the author as one of the three great jurists and Muhaddiths…